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The concrete is expected to have features like high fluidity, self-compact ability, high strength, high durability, greater serviceability and long service life of concrete structures. rationalised and labour-saving benefits in manufacture and placement of concrete SCC is a highly designed concrete which addresses these needs. In this work the SCC samples with different percentage addition of ggbfs, fly ash and polypropylene fibres cured with Concentrated Sulphuric acid (H2SO4) and Sodium hydroxide (NaOH) at the period of 60, 80 and 120 days and it was tested under the temperature of 200 °C and 400 °C and it was tested for the compressive strength. Comparing the results with the samples without addition of polypropylene fibres (1% and 2%) there is a marked improvement in the compressive strength.

A large-span steel–concrete composite beam with precast hollow core slabs (CBHCSs) is a relatively new floor structure that can be applied to various long-span structures. However, human-induced vibrations may present serviceability issues in such structures. To alleviate vibrations, both the walking forces excited by humans and the associated floor responses must be elucidated. In this study, 150 load–time histories of walking, excited by 25 test participants, are obtained using a force measuring plate. The dynamic loading factors and phase angles in the Fourier series functions for one-step walking are determined. Subsequently, walking tests are performed on seven CBHCS specimens to capture the essential dynamic properties of mode shapes, natural frequencies, damping ratios, and acceleration time histories. The CBHCS floor system generally exhibits a high frequency (> 10 Hz) and low damping (damping ratio

Hong Kong has a long history of applying masonry retaining walls to provide horizontal platforms and stabilize man-made slopes. Due to the sub-tropical climate, some masonry retaining walls are colonized by trees. Extreme weather, such as typhoons and heavy rains, may cause rupture or root failure of those trees, thus resulting in instability of the retaining walls. A monitoring and warning system for the movement of masonry retaining walls and sway of trees has been designed with the application of fiber Bragg grating (FBG) sensing technology. The monitoring system is also equipped with a solar power system and 4G data transmission devices. The key functions of the proposed monitoring system include remote sensing and data access, early warning, and real-time data visualization. The setups and working principles of the monitoring systems and related transducers are introduced. The feasibility, accuracy, serviceability and reliability of this monitoring system have been checked by in-site calibration tests and four-month monitoring. Besides, a two-level interface has been developed for data visualization. The monitoring results show that the monitored masonry retaining wall had a reversible movement up to 2.5 mm during the monitoring period. Besides, it is found that the locations of the maximum strain on trees depend on the crown spread of trees.

This paper presents a thorough study of particle impact breakage in selection function with a unified breakage criterion. The impact mode and breakage pattern for particulate materials are classified based on a significant review of well-established impact testers. It was found that the lack of a unified breakage criterion to determine the breakage probability disables a direct comparison of particle breakage propensity from different impact loading testers. The literature breakage models to describe the breakage probability are reviewed where the advantage and drawback of these models are scrutinized. The sourced literature breakage models are compared with the zeolite breakage datasets in a unified breakage criterion to evaluate the model performance. A novel computational modelling workflow for a milling process is proposed to provide a guidance in implementing the digital twin in milling process prediction. The breakage probability models, i.e. the selection functions are comprehensively assessed in population balance model to examine the model serviceability. The model simplicity and fidelity in the model assessment are specifically discussed and the value of digital twin in substantially reducing the experimental trials is highlighted.

The high cost and time involved with traditional road pavement monitoring approaches as well as the high costs of pavement monitoring equipment necessitate the need for introducing a cheap, accurate and straightforward road pavement monitoring method. Pavement monitoring systems are considered as an important preventive step to maintain the quality of road pavements. Road pavement conditions should be accurately monitored to measure the severity of road pavement degradations. This paper presents a new technique for road pavement monitoring. The proposed road pavement monitoring technique applies road pavement vibration measurements from an e-bike and a private sedan car equipped with vibration data and video recordings. In addition, a pavement performance indicator named Present Serviceability Rating (PSR) is used to detect the level of pavement degradation and overall pavement condition depending on visual inspections. The results from the proposed vibration monitoring technique and the PSR are compared to identify the accuracy of the proposed technique to measure the road pavement condition. The results of the case study road show that the e-bike and the sedan car are appropriate and accurate as test vehicles in pavement monitoring. They also show that travel speed and the number of monitoring iterations have a significant impact on the accuracy of pavement vibration data and consequently, on the accuracy of the road pavement monitoring of both test vehicles.

The serviceability limit state (SLS) design of foundations typically proceeds by limiting the total settlement of individual foundations and thereby attempting to restrict the differential settlement between pairs of foundations. Due to the uncertain nature of the supporting ground, the magnitude of settlement and differential settlement are random. As it is often the differential settlement that governs serviceability, it is desirable to provide design requirements that suitably restrict differential settlements. This paper investigates, by Monte Carlo simulation, the distribution of the maximum differential settlement between pairs of foundations as a function of the spacing between foundations and the number of foundations — groups of four, nine, or 16 foundations, arranged on a grid — are considered. The effects of the correlations between the equivalent stiffness of the ground under each foundation, as well as between the loads applied to the foundations, on the distribution of the maximum differential settlements and angular distortions are investigated. Ratios of resistance factor to resistance bias factor are presented that can be used to calibrate design requirements on the total settlement of individual foundations that also simultaneously achieve acceptable performance with respect to angular distortion.

The geometry of the structure and internal bar forces under varying service load situations or prestressing actually impact on the structure’s serviceability. Or else, prestressed cable structures ...

Excessive structural forces generated inside tunnel linings could affect the safety and serviceability of tunnels, emphasizing the need to accurately predict the forces acting on tunnel linings during the preliminary design phase. In this study, an anisotropic soil model developed by Norwegian Geotechnical Institute (NGI) based on the Active-Direct shear-Passive concept (NGI-ADP model) was adopted to conduct finite element (FE) analyses. A total of 682 cases were modeled to analyze the effects of five key parameters on twin-tunnel structural forces; these parameters included twin-tunnel arrangements and subsurface soil properties: burial depth H, tunnel center-to-center distance D, soil strength s u A , stiffness ratio G u / s u A , and degree of anisotropy s u P / s u A . The significant factors contributing to the bending moment and thrust force of the linings were the tunnel distance and overlying soil depth, respectively. The degree of anisotropy of the surrounding soil was found to be extremely important in simulating the twin-tunnel construction, and severe design errors could be made if the soil anisotropy is ignored. A cutting-edge application of machine learning in the construction of twin tunnels is presented; multivariate adaptive regression splines and decision tree regressor methods are developed to predict the maximum bending moment within the first tunnel’s linings based on the constructed FE cases. The developed prediction model can enable engineers to estimate the structural response of twin tunnels more accurately in order to meet the specific target reliability indices of projects.

Wind turbine generators (WTGs) are expected to provide active power control (APC) to track active power instructions from wind farm operators. Because the regulation of turbines mechanical dynamics depends on pitch angle regulation, mitigating frequent pitch adjustments is a key issue and accordingly several rotor speed variation-first APC methods were proposed to decrease pitch servo fatigue. However, due to lack of a quantitative description on the utilization of rotor speed variation (RSV), the ability of reducing pitch action through RSV can hardly be analyzed and compared among the existing APC methods. Hence, the disturbance range of nonpitch regulation (DRNP) and the maximum DRNP are defined in this paper. The former represents the effect of pitch action mitigation through RSV with a specific APC strategy and provides a unified foundation for quantitatively evaluating and selecting APC methods from the perspective of pitch servo serviceability. The latter, which depends on the turbine specifications and is independent of the control method, represents the maximum effect that can be achieved for a WTG. On this basis, an improved APC method is proposed to further reduce pitch servo fatigue. Finally, the DRNP indicators and the effectiveness and feasibility of proposed method are verified by the wind turbine simulator-based experiments

Bridges are the essential parts of the transportation facilities and are subjected to various forces depending on the onsite conditions and specific location of the bridge. T-beam bridges are pivotal in commuting from one place to other especially in shorter spans. The major forces acting on the T-beam bridges are static load, moving load and seismic load. Design of the T-beam bridges is conventional and versatile, as the main components are beams and slabs. There are various methods for the design of RC bridges, depending on the safety and serviceability. The earlier bridges were designed based on the working stress method as safety was the only criteria. Nowadays, the design is based on safety and serviceability. Most of the short span bridges in India are constructed as per the design details of standard plans by Ministry of Surface transport, Govt. of India. The complete design details for RCC slab and T-beam bridges (volume II) are available for the span ranging from 10 m to 24 m. The design details are established on the basis of working stress method as per code IRC 21: 1987. Provisions of IRC-6:1985 for seismic loading has also been incorporated in the design details. At present, working stress method of design of RC Road bridges has been outdated and IRC 112: 2011 code is in use. The study is about, to check the suitability of standard design drawings for spans varying from 10 m to 24 m based on limit state guidelines. design details are checked for the suitability at all seismic zones. MIDAS Civil (2019) software has been adopted to conduct this study. Comparative study has been made for the suitability of the design details of all spans in all seismic zones as per the new code.

Friction dampers are widely used in structural vibration control to mitigate seismic risks. In literatures, many different friction damper designs have been proposed, tested and implemented, but most studies concerned the performance of newly fabricated dampers and very few considered their long-term behavior. Since most friction surfaces are made of metals, corrosion or grease contamination during the lives of dampers may occur, and subsequently their energy dissipating characteristics may be adversely affected. In this study, the effects due to different serviceability conditions of a linear motion friction damper are investigated. It begins with experimental investigations of damper specimens with four different serviceability conditions: (1) polished and dry, representing as-new condition, (2) polished and greased, representing a contaminated condition, (3) rust and dry, representing a long-term condition and (4) rust and greased, representing a long term and contaminated condition. Force-displacement hysteresis is obtained under cyclic loads. Coefficients of friction are calibrated from finite element models. It was found that the coefficient may reduce from 0.7 (as new, polished condition) to 0.16 (rust and greased condition). Energy dissipation is reduced by 56% in the experiments. In a following numerical investigation, such serviceability conditions are applied to a numerical building model subjected to earthquake ground motions. Results indicated that, corrosion and grease contamination diminish the effectiveness of dampers. In the worst scenario, the beneficial effects of added friction dampers is entirely removed if rust and grease is allowed to build up on friction surfaces.

A design algorithm is proposed for rational seismic design solutions of steel buildings associated with buckling restrained braces (BRB). The strengths and locations of BRBs in addition to the section sizes of structural members are considered as discrete design variables. The steel volume including BRBs is minimized as an objective function under various practical design constraints. A seven-story office building is examined for application in two different types of structural systems, i.e. one mainly consisting of lateral frames and the other with limited utilization of lateral frames typically in perimeter separately from gravity frames. The derived solutions, defined as superior design solutions (SDSs), satisfy serviceability and limit-state constraints, taking into consideration the seismic energy dissipation effect of BRBs using the calculation of resistance and limit-state method. Their rationale is validated with response history analysis. Furthermore, the influences in SDSs by the seismic demand levels and elastic member constraint are investigated. The structural characteristics of SDSs associated with BRBs are objectively evaluated using the proposed design algorithm.

The suspended floor is a relatively new form of floor system in the suspended structure. Owing to the special boundary condition where the whole floor is lifted by cables rather than supported by columns or walls, the suspended floor is flexible and may face the issue of vibration serviceability. In this study, a composite floor lifted by carbon fiber-reinforced polymer (CFRP) cables used for small-scale exhibitions was designed and constructed, and field measurements were conducted to study dynamic characteristics and human-induced vibration serviceability of the suspended floor. The dynamic characteristics test using the natural excitation technique was conducted first, and the fundamental frequency of the floor was determined as 5.08 Hz. Then, the effects of pedestrian number and weight, walking frequency and route, and jumping point and frequency were discussed in the human-induced vibration test. Test results indicated that floor vibration responses increased with the pedestrian number, and increased as the jumping (walking) frequency approached the floor’s fundamental frequency. Higher vibration responses were obtained when the human-induced vibration was exerted on positions with less vertical vibration constraints. Vibration serviceability assessment using peak acceleration and root mean square (RMS) acceleration methods neglecting the effect of vibration duration show that the floor can meet the requirement in public places without excitations like walking at high frequency or rhythmic jumping, whereas vibration dose value/ estimated vibration dose value (VDV/eVDV) methods considering vibration duration tend to give a better comment. This study provides a fundamental basis to fill the lack of research on the vibration serviceability of the suspended floor.

The vibration control of a cantilevered floor with tuned mass dampers (TMDs) was investigated using dynamic testing and numerical simulation methods to better satisfy the structural serviceability requirement. The human-induced vibration response under walking and running conditions were firstly presented based on a series of dynamic testing with a single pedestrian and groups of pedestrians. A fast-evaluated frequency response function (FRF) method suggested by AISC Design Guide 11 was also used to evaluate the vibration response and further verified by the dynamic testing. A passive TMDs system was applied to reduce the vibration response; the vibration control of the cantilevered floor with TMDs was also evaluated by the dynamic testing with a single pedestrian and groups of pedestrians. The results showed that the maximum acceleration response of the cantilevered floor under the running load exceeded the limit, which was on average nine times that of the values under the walking condition. The FRF method could provide a fast and conservative vibration evaluation, in which the maximum acceleration response was 26% higher than that from dynamic testing. The acceleration response was significantly reduced with a maximum reduction effect of 64% after the installation of TMDs, resulting in satisfactory vibration serviceability of the cantilevered floor; the numerical simulation of that agreed well with the dynamic testing results. The vibration control of the cantilevered floor as a case study can serve as reference for the application of TMDs.

Nowadays, vibration serviceability criteria are becoming the governing factor in the design of most modern staircases, because their increasing susceptibility to human induced vibrations. Although more awareness have been raised to the dynamic design of new staircases, there are still few studies found in the literature that compare the different results of numerical methods for predicting vibrations with experimental data, in order to validate the same. Hence, this paper employs the main existing numerical methods to an actual staircase with known liveness, by comparing the predicted results with the experimental data, to evaluate their accuracy when designing flexible staircases. This paper is Part 2 of a set of two papers. In Part 1, the different numerical methods are presented and details are given of how to apply them. To accomplish this, an in-situ staircase dynamic characterisation and several walking tests are performed. The measured vibrations are initially compared with different proposed acceptable limits to confirm that the vibrations exceed the limits. The different numerical methods are then employed and the predicted results are compared with the experimental results. Lastly, the main findings of this work are discussed together with those of diverse researchers who also applied one of these procedures to estimate vibrations. The results obtained showed that, with two of the numerical procedures applied (footfall force time histories and simplified vibration evaluation), it was possible to effectively predict the vibrations, while with the remaining two (Fourier series walking models and steady-state analysis), in general, overestimated responses were predicted.

Although most of the concrete beams on site are continuous RC girders, there is a lack of interest in the design equations for those concrete elements and the redistribution of moments between critical sections which is a major factor in this design. This paper aims at developing models of 3D nonlinear finite elements (FE) and investigating numerically the influence of the steel reinforcement in the sagging and hogging regions on the performance of the RC continuous T-beams and their effect on the moment redistribution and improvement of the design equations by using the authors' experimental specimens for verification. The two-span RC continuous beams with a loaded central concrete column were manufactured and tested to failure. Forty-one specimens with different lengths were simulated by constructing a FEM, ranging from 2: 10 m for each span, in order to simulate according to reality. The results show that the sagging reinforcement improves the ductility and the serviceability of the continuous beams at the allowable deflection and the permissible crack width. The moment redistribution ratio depends on the ratio between the sagging reinforcement and the hogging reinforcement areas. The described FEM could predict the behaviour of the experimental specimens with acceptable precision.

Experimental tests on rack joints have shown that the cyclic response of beam-to-column joints, which in steel storage pallet racks is usually affected by pronounced pinching, could be significantly improved if joints are equipped with bolts. Bolts allow for ultimate moment, ductility, and dissipated energy of joints to be increased. Nevertheless, their installation in all joints of a rack system would be uneconomical and would nullify advantages of traditional boltless dry connections, which allow for beams to be easily disconnected if a new corridor or free space is required. The selective addition of bolted joints and its influence of the seismic response of rack systems is the focus of the manuscript. Different layouts of rack systems, with bolted connections only in some specific positions, are studied and compared. The addition of bolted connections improves the serviceability behavior, as the displacements of the system are reduced. Concerning the seismic capacity, the beneficial effect of bolted connections is appreciable only if seismic actions are sufficiently high and connections undergo plastic deformation. Configurations with bolted connections located only at the lowest levels allow to achieve a similar structural performance of a fully bolted configuration, saving the cost of the structure.

In the design of high-rise buildings, the lateral structural system that resists seismic and wind actions often dominates the overall design, and as a result, the optimum design of the lateral structural system is important for material efficiency. This paper aims to present a new design methodology that relies on an extended Evolutionary Structural Optimization (ESO) method to optimize the shear wall layout for the design of high-rise buildings. By discretizing all the shear walls of the ground structure into wall elements, different shear wall layouts were described by a binary matrix where ‘0′ and ‘1′ indicate the absence or presence of a wall element respectively. The proposed framework borrowed the intuitive concept of the ESO method, where the less stressed wall elements in the structure were gradually removed but the highly stressed wall elements were reserved. The conceptual design method was combined with the optimization algorithm to control the optimization process and to reduce structural eccentricity considering architecture, strength and serviceability constraints. Then, the structural weight could be automatically minimized under multiple loading cases and design constraints. By integrating the commercially available ETABS, a dedicated optimization software with an independent interface was developed and details were also presented in this paper for practical software development. The proposed framework was used to optimize the layouts of different shear wall structures, and case studies showed that the proposed framework could optimize shear wall structures with a material saving of up to 14% compared to the conventional design, which proved the feasibility and effectiveness of the framework. The paper can therefore be referenced by other researchers and software engineers to further explore the layout optimization of shear wall structures and to reduce material usage for a more sustainable design.

The dynamic response of modern slender footbridges is usually sensitive to both the pedestrian actions and the uncertainties associated with their inherent structural behavior. Thus, tuned mass dampers have been widely integrated in the design of these structures to guarantee the fulfillment of the vibration serviceability limit state during their overall life cycle. Three different techniques of tuned mass dampers (active, semi-active and passive) are usually considered for this purpose. Although there are algorithms for the robust design of each particular technique, however, this specificity makes difficult the implementation of all these techniques in practical engineering applications. Herein, the motion-based design method under uncertainty conditions is proposed and further implemented to create a common framework for the robust design of all these techniques when they are employed to mitigate pedestrian-induced vibrations in slender footbridges. According to this method, the design problem may be transformed into the combination of two sequential sub-problems: (i) a reliability multi-objective optimization sub-problem; and (ii) a decision-making sub-problem. Subsequently, the performance of this proposal has been validated through a numerical case study in which the dynamic response of a steel footbridge has been controlled by three different tuned mass damper techniques designed according to the proposed common framework.

This The influence of fibre reinforcement on crack propagation in concrete was studied . Thirty-five double torsion specimens, made with three types of fibres (fibre glass , straight steel fibres and deformed steel fibres ) were tested . The variables were the fibre volume and size of the fibres. The test results indicated that the resistance to rapid crack growth increased somewhat with increasing fibre content up to about 1.25% - 1.5% by volume. The degree of compaction had an enormous effect on the fracture properties .The fracture toughness increased with fibre content up to about 1.25% by volume, and then decreased , due to incomplete compaction. It was found that in this test geometry, fibres did not significantly restrain crack growth. It was also observed that once the crack had propagated down the full length of the specimen, the system changed from a continuous system to a discontinuous system, consisting of two separate plates held together by the fibre reinforcement. Different types of fibres did not significantly affect the fracture toughness. Keywords: Fibre glass, straight steel fibers, deformed steel fibers, fracture toughness.

Розглянуті особливості виготовлення гумових гофрованих рукавів для вузлів стикування системи термостатування космічних ракет. Ці особливості пов’язані із властивостями гуми як конструкційного матеріалу і особливостями технології виготовлення великогабаритних гумотехнічних виробів, до яких відносяться зазначені гумові рукави, формовим способом. Оскільки технологія і спосіб їх виготовлення нерозривно пов’язані з конструкцією технологічного оснащення, розглянуто принципово новий підхід при виготовленні гумових рукавів високої якості декількох типорозмірів одного діаметра різної довжиии в одній прес-формі з можливістю її переналагоджування. Новий підхід полягає в тому, що в прес-формі для виготовлення відповідного гумового рукава в верхній і нижній плитах з внутрішньої сторони вздовж осі попарно симетрично установлюють змінні секційні сегменти, а на суцільну частину розбірного стрижня установлюють змінні діаметральні вкладиші, з допомогою яких забезпечується формоутворення гумового гофрованого рукава відповідних розмірів одного діаметра. При цьому центри поверхонь виступів і западин вкладишів повинні співпадати в площині з відповідними центрами поверхонь западин і виступів змінних секційних сегментів у нижній та верхній плитах прес-форми. Геометричні розміри змінних секційних сегментів та діаметральних вкладишів залежить від геометричних розмірів кожного рукава і кількості гофр на ньому в межах одного діаметра. Це дає можливість мінімізувати витрати на виготовлення та ремонт технологічного оснащення за рахунок зменшення його кількості та підвищити ремонтопридатність технологічного оснащення і його якість за рахунок підвищення технологічності виготовлення і ремонту деталей прес-форми, що забезпечують формоутворення гумового гофрованого рукава для вузлів стикування системи термостатування. На спосіб виготовлення рукавів стикування трубопроводу системи термостатування отримано патент на корисну модель від 27.07.2020 року №143346. Показана можливість підвищення продуктивності праці з виготовлення гумових гофрованих рукавів для системи термостатування за рахунок виготовлення другого взаємозамінного стрижня і його підготовки до експлуатації в процесі здійснення технологічного процесу.

Bridges are a critical part of transport infrastructure networks for social activities and economics of human life. Dynamic analysis of bridge is very important to perform in order to ensure the ability of the bridge to withstand loads and maintain the sustainability of transport infrastructure. This paper presents a methodological framework for monitoring dynamic behavior of the bridge (e.g., natural frequencies, displacement time history) by using civil engineering micro-tremor technique and numerical modeling. The study was conducted at the Alue Raya Bridge located in Lhokseumawe City, Aceh Province, Indonesia. To capture the dynamic behavior of the bridge under traffic loading, the micro-tremor techniques, e.g., Short Period Seismograph (SPS) sensor was placed underneath the bridge at the mid span of the bridge girder. The obtained vibration data were processed using Geopsy software. A three dimensional (3D) model of the bridge was then developed by using CSI Bridge software. The modal analysis was conducted to obtain the modal natural frequencies of the bridge due to traffic loads. The natural frequency measurements using SPS were compared with the simulation results. Through analyzing the measured results, it was found that the natural frequency of the bridge is around 4,3275 Hz which is very close to those obtained from numerical modeling using CSI bridge software. The measured maximum vertical displacement of the bridge girders is below 5mm under normal traffic condition which is under the allowable serviceability limit state requirements of the bridge. The outcomes of this study could have the potential to enable maintenance and capital works decisions which are an important component of the sustainability of transport infrastructure.

The hinge type of precast concrete arch culvert was introduced to Japan from France in the 1990s in consideration of the saving of labor, shortening of the construction period, and high quality control of the concrete members. However, due to the 2011 off the Pacific Coast of Tohoku Earthquake (March 11, 2011), the three-hinged precast arch culverts that had been constructed in Japan at the beginning of the period when precast arch culverts were firstly introduced, suffered damage, which spoiled their serviceability. According to the extent of the damage and the type of culverts that were damaged, the longitudinal structural connectivity of the culverts was assumed to be one of the possible reasons for the reported damage mechanism. Therefore, the objective of this paper was to clarify how strongly the longitudinal structural connectivity influenced the longitudinal seismic behavior of the three-hinged arch culverts. To achieve this objective, an elasto-plastic finite element analysis was conducted with an analytical model that could capture the characteristics of the damaged culverts. Simultaneously, a penalty method with the bi-linear spring model was applied as a solution to the contact-impact problems of the precast segmental arch members. As a result, it was found that the weaker longitudinal structural connectivity in the damaged culverts allowed the torsional displacements of the arch members to induce critical damage to the arch members, namely, edge defects in the arch crown and concrete foundation. The numerical results proved the unignorable influence of the longitudinal structural connection on the possible damage to three-hinged arch culverts.

The monitoring of bridge dynamic displacement under normal operation conditions has been a vital need for the assessment of the serviceability of bridges. Traditionally, it was mostly accomplished by the Global Navigation Satellite System (GNSS). However, the poor measurement accuracy and low sampling rate of the GNSS limit the use of monitored displacement signals. In this paper, we propose a novel adaptive multirate Rauch-Tung-Striebel (RTS) smoother that fuses the measurement signals of GNSS and accelerometers to improve both accuracy and sampling rate. The proposed algorithm distinguishes itself from previous studies by adaptively estimating the unknown time-varying transition and GNSS measurement noise variances using the variational Bayes (VB) technique, making it more accurate and less human-involved. The proposed algorithm was validated on a field test conducted on Chishuihe Hongjun Bridge in China, which has the second longest main span and the second highest main towers among suspension bridges over valleys in the world. The algorithm estimated the dynamic displacement at an accuracy of 2.09 mm, which is 21.4% better than the result of the previous algorithm, with both pseudo-static and several low-order main vibration mode components recovered.

Background Proper cement selection in fixed prosthesis plays a determinative role in providing long-term serviceability, retention, caries prevention, and patient satisfaction. This study, reviews different luting agent characteristics and their application based on different clinical situations and different types of full coverage restorations. Material and methods An electronic search was conducted through PubMed, Medline, and Google scholar using following keywords or combinations: restoration, full coverage, PFM, porcelain fused to metal, all ceramic, zirconia, ceramic, casting, fixed partial denture, cement*, dental cement, cement selection, and retention. The most related articles were selected for review. Results Choosing a proper luting agent is highly dependent on scientific knowledge regarding the characteristics of restorative materials and luting agents. Conventional cements could be indicated in various situations; however, some restorative materials or clinical situations call for resin-cements to provide predictable retention, support, and durability. Conclusions Conscious selection of retentive cement for each type of restoration/material is necessary to provide predictable successful treatment and reduce the potential complications. Key words:Adhesive cement, dental bridgework, dental cements, dental crowns, dental porcelain, prostheses and implants.

G��otechnique 71(11), 957-969 (2021). doi:10.1680/jgeot.19.SiP.038, Published by ICE Publishing, London

Producing high-performance and long-lasting rigid pavements is a complex process that integrates appropriate design and materials, quality construction practices, timely maintenance, and overall adequate pavement management. The design of pavements requires more than "thickness design" for carrying flexural stresses. Structural design is based on the concept of limiting stresses and deformations to prevent excessive damage and deterioration of pavements. Recommendations for dowel diameter size should be based on the thickness of the pavement slab. FHWA recommends that the minimum dowel diameter should be at least one-eighth the pavement thickness. The American Association of State and Highway Transportation Officials (AASHTO) method relates the axle equivalency method to the pavement damage based on loss of pavement serviceability as related to the standard 18 kip single axle load. The Portland Cement Association (PCA) method determines the damage caused by each vehicle type in the traffic stream and accumulates the total damage over the life span of the pavement.

The durability of concrete material after exposure to elevated temperatures is important for the serviceability prediction of concrete structures in a fire disaster scenario. Existing researches show that an appropriate amount of basalt fiber can significantly improve the splitting tensile strength and chloride penetration resistance of concrete. However, the mechanical properties of basalt fiber concrete after elevated temperatures and its durability properties are still not clear. In this paper, the mechanical properties, carbonization law, and chloride ion penetration law of ordinary concrete and basalt fiber concrete under high temperatures are studied. The concept of a burnt layer for concrete exposed to elevated temperatures is proposed, and the thickness of this burnt layer for concrete under different temperatures was measured. The results show that the addition of basalt fiber can inhibit the carbonization of concrete at elevated temperatures, diminish the thickness of the burnt layer, and significantly improve the chloride penetration resistance of concrete.

The present study proposes an optimal design methodology of tuned liquid sloshing dampers (TLSDs) installed in wind-excited benchmark tall building. The TLSDs design parameters were determined using proposed optimal design methodology based on nonlinear constraint optimization technique. Top floor peak acceleration was considered as the objective function and maximum value of sloshing depth of liquid as a nonlinear constraint for the design purpose. The classical nonlinear shallow water wave theory was used for the simulation of liquid sloshing, and the basic equations of nonlinear liquid sloshing were solved using the Lax Finite Difference Scheme. The governing equations of motion of combined structure-TLSDs system were expressed as state-space variables and structural response was numerically simulated. The findings were presented and assessed on the basis of a comparison between power spectral density functions, time history analysis, root mean square, peak response, and performance criteria for benchmark building with and without TLSDs. The off-tuning effect of TLSDs due to ± 15 % uncertainty in the building stiffness was also investigated. Further, an attempt has been made to present the control effectiveness of TLSDs in time–frequency domain (wavelet scalogram) using continuous wavelet transformation technique. The optimal TLSDs design based on the proposed methodology was found to be quite effective in serviceability-based design of benchmark tall building under wind loads and can be very useful for the practical design of TLSDs.

The long-term leakage of lining under train loading has a significant impact on the consolidation settlements around shield tunnel and the rheological behaviour of viscoelastic porous soils will further exacerbate this consequence, which adversely affect the adjacent geo-environments and the subsidence of existing structures. At present, the assumptions of tunnel impermeable lining and liner-elastic clays are usually received to conduct on the consolidation settlements. Moreover, little attention is paid on the coupled influence of lining leakage and train loading. For better engineering serviceability in viscous porous clays, this paper presents a closed-form analytical solution for predicting the ground consolidation settlements under train loading considering the lining leakage and the rheological medium, with the scope of Terzaghi-Rendulic theory. By introducing semi-permeable boundary condition, the triangular cyclic loading is equivalently applied to the tunnel lining and the Boltzmann viscoelastic model is employed to simulate the rheological characteristic of the actual geology. The dissipation solution of excess pore water pressure and the ground responses in viscoelastic porous clays are derived using the conformal mapping. In addition, the accuracy of the analytical solutions is verified by comparisons with in-situ observed data and existing numerical simulation results from the engineering cases, showing reasonable alignments. The differences between the Kelvin and Boltzmann model are further analyzed to estimate the influences of rheological geology. Furthermore, a detailed sensitivity analysis is also implemented to investigate the performance of concerned parameters on the surface consolidation settlements, including the lining-soil permeability, the parameters of Boltzmann model (elasticity module Eh in the Hoek body, elasticity module Ek and viscosity coefficient ηk in the Kelvin body), and the train loading. The interesting point and ingenious approach in this study are tracing the corresponding analytical solutions on the consideration for not only the coupled influence of lining leakage and train loading but also the rheological behaviour in the viscoelastic porous soils.

Major aspects that were considered while designing a structure are safety and serviceability. Serviceability is also called as life span of structure reduces, when exposed to severe environments. Solid waste management in developing nations has been growing everyday, which influenced the scientists and researchers around the world in recycling and application of solid waste in various fields. Introduction of waste and recycled fibers in concrete is quite prominent from last few decades. In this research, electric waster copper fibers (EWCF) are added to concrete to test mechanical properties and chloride ion penetration that could reduce the durability of concrete. Adopted percentages of copper fibers added to the concrete are 0, 0.25, 0.5, 0.75, 1.00, 1.25, 1.50, 1.75 and 2.00 for volume of concrete. Concrete introduced with EWCF was tested for compression, tensile, flexural and elastic modulus to determine mechanical behavior. Most optimal EWCF percentage of replacement that increased the strength of concrete is 1.0% in volume of concrete. Water absorption, sorptivity, acid attack, bulk diffusion and rapid chloride penetration test (RCPT) were performed on concrete with EWCF to evaluate the durability and microstructure performance. E-Glass and Steel fibers were also adopted in the study to compare the mechanical properties and durability. Optimum values for both strength and durability were determined from the experimental test results.

Material efficiency is not currently a common driver of building design. Indeed, in previous studies, we estimated that 12% of the mass of steel used in structural frames would be saved by more accurate specification of steel members. However, this inefficiency is not the main reason structural frames are light or heavy. We show here for the case of steel structures that it is the layout of the grid and the choice of the decking which have the largest impact on the embodied carbon of frames. Using a database of real designs, associated to a generative design model, we quantify the impact of grid and decking selections. Using our model, we find that real designs are relatively efficient economically, but less so environmentally: the typical building frame could have 40–60% less embodied carbon, and be approximately 10–20% cheaper with the right selection. We show how more complex frames have higher embodied carbon than simpler grids. From our findings, we establish a list of design considerations that architects and structural engineers should account for when creating an initial design to lower the embodied carbon: the complexity of the layout, the optimisation of the design and the choice of the decking technology.

Civil infrastructures deteriorate due to aging, adverse environmental conditions, and inadequate maintenance. Thus, to ensure both safety and serviceability of the structures as well as to mitigate economic losses, it is essential to employ a comprehensive structural health monitoring (SHM) system and appropriate damage identification procedure. Finite element (FE) model updating is one of the most common approaches of damage detection in civil engineering. The most widely used techniques for FE model updating have been developed based on data in the time, time–frequency, and modal domains. In this study, a novel damage identification technique is proposed based on wavelet packet transform component energy (WPTCE). The discrepancy between WPTCE of intact and damaged states of the structure was considered as a residual in the sensitivity-based FE model updating procedure. Two numerical examples, namely a two-dimensional truss bridge and a double layer diamatic dome was used to illustrate the efficiency and applicability of the proposed method in structural damage identification. Sensitivity analysis showed that the WPTCE is a highly sensitive response to structural damages. Further, the results revealed that the proposed method leads to accurate detection of damage, though the measured signals are contaminated by noise.

Slender footbridges with long spans and light materials may lead to serviceability problems in lateral vibrations due to walking pedestrians. The phenomenon, known as the “lock-in effect” occurs when the number of pedestrians on the footbridge reaches the “critical number”. Considering the mode of vibration in which the instability is more likely to develop, the footbridge response depends on the structural natural frequency and modal damping ratio. These parameters may not have a fixed value during the footbridge overall life cycle due to environmental and operational changes. Therefore, lateral vibration serviceability procedures should include the uncertainty in the footbridge modal parameters in the most simple and applicable way, as the dynamic response of slender footbridges is very sensitive to these uncertainties. Hence, this paper proposes a simple approach, useful for practical engineering applications, to assess the lateral vibration serviceability of slender footbridges, considering the uncertainties in natural frequency and modal damping ratio. The uncertainty is considered by two approaches: probability theory and possibility theory (fuzzy sets). As a result, the study allows checking the vibration serviceability criteria over a range of levels of uncertainty, suggesting that the external factors that affect the modal parameters are more significant when the crowd density exceeds the critical number. The study also shows the simplicity and effectiveness of the possibility theory to deal with the uncertainty in modal parameters, although for similar level of uncertainty, the dynamic response is slightly higher than using the probability theory. Finally, the proposal is applied in two real footbridges, showing a good agreement with the experimental data.

A novel method for bamboo scrimber strengthening timber beams with anchorage structures was proposed. Bamboo scrimber was adhered to the bottom of the timber beam and anchored with carbon fiber-reinforced polymers (CFRPs) or wooden pins. Through the bending tests of eight reinforced beams and two control beams, the effects of different forms of anchorage and thicknesses of bamboo scrimber on the strengthening effect of timber beams were studied. The failure characteristics of the timber beams were observed, and the ultimate load, stiffness and ductility were analyzed. The results show that the failure modes of timber beams can be divided into bending failure and bending-shear failure and that the timber beams exhibit obvious signs of ductile deformation before failure. The ultimate bearing capacity of the reinforced beams increased by approximately 20%–70%, and the cross-sectional stiffness at the serviceability limit state increased by approximately 40%–160%. The test results confirm that CFRPs and wooden pins can firmly adhere to the timber beam and bamboo scrimber, so the bamboo scrimber strengthening timber beams with anchorage structures can substantially increase the ultimate bearing capacity and stiffness and improve the ductility of the member.

Another effective way to achieve sustainability in civil engineering is to push the service life of the structural members from the environmental effects. It has been reported that well-maintained slabs have performed sound during their service life as compared to the degraded one over a short period of time due to poor maintenance. Cracking and deformation of slab over the sustained load is one of the most important aspect related to serviceability. The deflection and crack propagation can be minimized by the application suitable retrofitting technique using locally available material and also enhance flexural capacity. The main purpose of this examination is to utilize the flexural properties of the natural fibers, such as Jute and Coir, these fibers are chemically treated to enhance both mechanical and durability properties. Total five slabs are cast, out of which one was regarded as controlled slab (CS) and the remaining four slabs are retrofitted by jute and coir fiber with varying percentage of the fiber content, respectively. Epoxy was used for the application of fiber on to slabs. Slabs were tested under static condition by applying uniformly distributed load over the slab through an arrangement called load spreader, and the results are tabulated. From the comparison of test results and with illustrated graphs it was observed, the first crack load and ultimate load increased.

The generalized indicator of useful use, depending on the state of individual elements of oil-producing equipment, characterizes the ability of this equipment to perform its function during operation at optimal working time. The generalized indicator of the useful use of operational equipment can be described as the calculated sum of the indicator of the useful use of individual equipment elements. If, during operation, the oil-producing equipment retains its operability due to frequent replacement of its structural and non-structural elements, then such operational equipment is considered by users as outdated. Operating equipment can be divided into 6 categories according to the indicators of suitability. The article analyzes the state of useful use of equipment and, as a result, the total utility of equipment is calculated in accordance with the indicators of useful use by category, and graphs of changes in the state of useful use are constructed. Based on the study of the graphs of the useful use of equipment, it was proposed to conduct an analysis in the following areas: • Evaluation of the design and technological perfection of the equipment by users according to important new parameters. • Determination of equipment compliance with wear standards during operation. Keywords: structural element, wear theory, the usefulness of jam, categories, schedule of changes, reliability.

Six lightweight aggregate concrete (LWC) beams reinforced with carbon fiber–reinforced polymer (CFRP) bars were tested under a four-point bending load with different steel fiber contents, reinforcement ratios, and clear span lengths to investigate their flexural behavior and serviceability performance. The test results showed that using steel fiber–reinforced lightweight aggregate concrete (SFLWC) and increasing the reinforcement ratio enhanced the serviceability performance of the beams. The incorporation of 0.6% by volume of steel fibers reduced the midspan deflection by 22.70%–36.87% at the same load level in service stage. At service load, all the CFRP-reinforced beams exhibited conservative deflections when compared to the deflection limits recommended by ACI 440.1 R and GB 50608, and satisfied the crack width limit of 0.7 mm. Comparing the measured maximum crack widths with the corresponding predictions revealed that the bond-dependent coefficient value of 1.4 specified in ACI 440.1 R was reasonable yet conservative. Moreover, an energy-based method was adopted to quantify the influence of the fibers on the beam stiffness. On this basis, a rational deflection model for SFLWC beams reinforced with CFRP bars was suggested.

During inspection of an 11-km-long pipeline made of API X60 steel carrying hydrocarbons containing wet H2S, hydrogen-induced cracking (HIC) was found at different locations along the pipeline length. Microstructural investigations by scanning electron microscopy (SEM) showed stepwise cracking (SWC) as the result of the presence of MnS inclusions. Fitness-for-service (FFS) assessment based on API579-1/ASME FFS-1 was performed to decide on the pipeline serviceability. The finite element analysis (FEA) results showed that the HIC-damaged pipeline was acceptable per level-3 FFS requirements and the pipeline understudy was fit for service. The remaining life of the damaged pipeline should also be periodically monitored using failure assessment diagram (FAD).

The vigorous development of communication technology, especially the development of wireless network communication technology, has accelerated its informatization process in more and more industrial applications. In the field of monitoring and detection applications, the many advantages of wireless network transmission technology provide an important reference for high-quality compaction monitoring. Engineering practice shows that the construction technology of asphalt pavement is the ultimate guarantee of engineering quality. It is important to recognize that pavement performance is greatly influenced by interface bonding condition and interface failure can reduce the serviceability of pavements rather than their overall structural lifetime. This paper presents a laboratory test to investigate the bonding tensile performance between asphalt layers by tensile testing. The test methods and devices for determining the bond regarding tensile testing are summarized as follows. Different interface conditions have been analyzed herein: 0.2, 0.4, and 0.6 kg/m2 with corresponding emulsified asphalt (MA) and SBS-modified MA. It is found that the stress-strain relationship of tensile testing for interface bonding is similar with low-carbon steels and it can be categorized into four zones. The results of tensile strength and damage displacement are discussed which are key parameters in describing the interface bonding condition and evaluating pavement performance.

Service is the basic technique in the Sepaktakraw game. Serve is the initial attack to earn points. To be successful in the implementation of this special technique in Sepaktakraw, a good physical condition and good psychological condition are needed. To see the effect of physical conditions and psychological conditions that have a direct and indirect effect on the ability to serve Sepaktakraw, a research on the ability to serve Sepaktakraw was carried out. The research method used is a quantitative method using a Path Analysis approach. The study population was the athletes of West Sumatra Sepaktakraw. The sampling technique was carried out by means of positive sampling and obtained 40 sepaktakraw athletes. The data obtained will be processed using data analysis techniques with the Path Analysis approach. The research instrument used are vertical jump for leg muscle explosive power, stand and rich test for flexibility, self-confidence questioner for self-confidence and service ability test instrument for service skill. The results showed that leg muscle explosive power has a direct effect on serviceability by 10.1%, flexibility has a direct effect on serviceability amounting to 39.81%, and self-confidence has a direct effect on serviceability amounting to 6.81%. Influence of explosive power through self-confidence on the service ability of sepaktakraw athletes is 19.2%. Influence of flexibility on serviceability through confidence in sepaktakraw athletes is 18.1%, and the influence of the variable explosive power, flexibility and self-confidence had an effect on serviceability amounting to 49.6%. However, the remaining 50.4% is influenced by other factors.

Many state transportation agencies are faced with making pavement rehabilitation decisions for roadways annually. Their design choices affect the future performance and maintenance cost of those pavements. This study determines if it is cost-effective to perform a field investigation (e.g., FWD, coring) for non-interstate routes to identify pavement structural and functional characteristics at the design stage and whether this information can aid in determining the most appropriate design for rehabilitation. To this end, field investigations are performed on 16 actual roadways (non-interstate routes) in the state of South Carolina prior to their rehabilitation, and an analysis was performed to compare the life-cycle cost between rehabilitation designs with and without field investigations. The results indicate that (1) the rehabilitation design with field investigation tends to produce a pavement that has the necessary depth and made up of higher strength materials that bring the pavement’s SN closer to the required value, (2) the rehabilitation design with field investigation defers the maintenance cycles, and (3) performing field investigation is cost-effective, particularly for those pavements that do not need maintenance treatments until their present serviceability index falls to a 2.

Rutting has a significant impact on the pavements' performance. Rutting depth is often used as a parameter to assess the quality of pavements. The Asphalt Institute (AI) design method prescribes a maximum allowable rutting depth of 13mm, whereas the AASHTO design method stipulates a critical serviceability index of 2.5 which is equivalent to an average rutting depth of 15mm. In this research, static and repeated compression tests were performed to evaluate the permanent strain based on (1) the relationship between mix properties (asphalt content and type), and (2) testing temperature. The results indicated that the accumulated plastic strain was higher during the repeated load test than that during the static load tests. Notably, temperature played a major role. The power-law model was used to describe the relationship between the accumulated permanent strain and the number of load repetitions. Furthermore, graphical analysis was performed using VESYS 5W to predict the rut depth for the asphalt concrete layer. The α and µ parameters affected the predicted rut depth significantly. The results show a substantial difference between the two tests, indicating that the repeated load test is more adequate, useful, and accurate when compared with the static load test for the evaluation of the rut depth.

Under long term wind load, the bolt looseness occurring at the joints of tower legs will reduce the wind-resistant capability, increasing the wind-induced displacement responses and affecting the serviceability of the high-rise steel tower. In order to detect the bolt looseness locations of the flange assembling joints of leg members in high-rise steel tubular tower structures, a new bolt loosening localization at flange joints method using wind-induced response for high-rise tower was presented in this paper. Wind-induced vertical strain response root variance of flange assembling joint on the tower vertical bar is defined as the identification parameter of the bolt looseness damage. Then, the normalized wind-induced vertical strain response root variance is defined as the damage index of bolt loose-ness damage, thereby eliminating the impact of wind loads of different magnitudes on damage identification. When the damage index exceeds the threshold, it can be considered that the bolt looseness damage occurs in flange assembling joint, thereby to realize the damage identification. The results both numerical analyses of a practical transmission tower and scaled model wind tunnel experiment of a steel tubular tower show that the proposed method is efficient and noise immunity on the bolt looseness location detection for high-rise tower.

The near field pulse-like ground motion has significant effects on a long-period structure like a wind turbine. Such pulses can be due to source effect (directivity) or site effect (presence of basins), to name a few. The presence of such pulses in the existing recordings of earthquakes is well documented. However, due to the paucity of such pulse-like recordings, simplified shapes have been proposed in literature in accordance with the observed features. In this study, the influence of characteristics parameters of earthquake velocity pulse on the monopile-supported offshore wind turbine (OWT) determined. The four parameters of velocity pulse, i.e., vp the velocity amplitude, fp the prevailing frequency, n number of pulse, and the α/β parameter of envelope function, are considered. To perform the incremental dynamic analysis, the numerical model of OWT is developed in open-source software OpenSees. The pulse-like ground motion parameters effects are shown in terms of fragility curves for the serviceability limit state and ultimate limit state.

El objetivo de este trabajo es explicar los conceptos detrás de los diferentes términos involucrados en la determinación de las propiedades del terreno en el marco de los Eurocódigos. El proceso comienza con todos los diferentes términos que aparecen en las fases de investigación y monitorización del terreno: valores históricos, valores estimados, valores de ensayo, valores monitorizados y valores derivados. Continúa con la determinación del “valor representativo” que es el valor que incide en la ocurrencia de los estados límite. Este valor se afecta por el factor parcial de materiales para obtener el “valor de proyecto” que será utilizado en la verificación de los diferentes estados límite último y de servicio de las estructuras geotécnicas utilizando el “Método de los Factores Parciales”. El futuro Eurocódigo 7 establece dos posibles formas de determinar dicho “valor representativo” de una propiedad del terreno: seleccionando el valor basándose en el juicio ingenieril y la experiencia comparable en casos similares, denominándose en este caso como “valor nominal”; o evaluar el valor por métodos estadísticos, denominándose en este caso “valor característico”. Además, el artículo ofrece un breve resumen del método estadístico para determinar el valor característico de una propiedad del terreno y un ejemplo del procedimiento a utilizar.

Rockfill dams are generally constructed on thick overburden layers in mountainous and valley areas due to their high adaptability to complex geological and geographical conditions. The safety of rockfill dams is a research focus worldwide, especially with the increase of dam heights. Significant differential settlement may be induced by different embankment materials in a dam body and various stratum properties in thick overburden layers. The accurate prediction of settlement is particularly important to guarantee the serviceability and safety operation of rockfill dams. Therefore, a novel settlement forecasting model is proposed in this study. This model can achieve a successful prediction of dam settlement during the construction and operation periods. Compared with the traditional model, the settlement influential factors in the proposed model are determined based on the existing theory of coarse-grained soil deformation calculation, causing the selection of factors to have clearer physical meanings. Additionally, the geometric characteristics of the dam, the different material properties in various zones of the dam and the foundation, and the complicated external loading conditions are all considered. Then, the improved regression model for forecasting the settlement of dams is proposed. The proposed settlement forecasting model is further employed to estimate the deformation of a high rockfill dam in China. The results prove that this novel method shows high accuracy and agrees well with the monitoring consequences, and this method is superior to the traditional statistical regression model in predicting dam settlement during the construction period.

Many analytical and numerical analysis and design methods for geosynthetic-reinforced soil structures require a single-value (constant) estimate of reinforcement stiffness. However, geosynthetic reinforcement products are rate-dependent polymeric materials meaning that they exhibit time and strain-dependent behaviour under load. Hence, the appropriate selection of a constant (elastic) stiffness value requires careful consideration. A simple hyperbolic stiffness model is shown to be a useful approximation to the constant-load isochronous creep-strain behaviour of these materials at low load levels applicable to operational (serviceability) conditions of geosynthetic-reinforced soil structures. A large database of 606 creep tests on 89 different geosynthetic reinforcement products falling within seven different product categories was collected. From these data, isochronous stiffness values were determined for different combinations of duration of loading and strain level. Data from products falling within the same category were collected together to provide approximations linking the isochronous load-strain (creep) stiffness to the ultimate tensile strength of the material. These approximations are useful for analytical and numerical modelling particularly when parametric studies are undertaken to identify the sensitivity of model outcomes to reinforcement stiffness. Finally, three different geosynthetic-reinforced soil application examples are provided to demonstrate the important role of tensile stiffness on analysis and design outcomes.

The formation and deposition of tufa precipitate from the leachate of the recycled concrete aggregate (RCA) within fibers of a nonwoven geotextile, as can potentially occur in a transportation infrastructure drainage system, is simulated in a laboratory environment. Two sets of modified column tests were conducted in this study with cycles of wetting and drying for 1 year in order to study the rate of RCA tufa precipitation. Results of measured changes in the infiltration capacities showed that, even with precipitated tufa, the RCA/geotextile system serviceability remains similar to the virgin aggregate (VA)/geotextile system at the end of the 12-month testing. Evaluation of the deposited tufa precipitation within geotextile samples showed that RCA tufa is dominated by calcite and gypsum minerals. Estimated quantities of RCA tufa deposition by existing models developed for natural environments, showed that they either grossly overestimate the observed behavior (calcite model) or underestimate it (gypsum model). Image analysis technique and chemical calculations based on leached dissolved solids were utilized successfully to develop models to predict the precipitation of RCA tufa in macroscales during the service life of a subdrain.