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Polyethylene terephthalate (PET) straps cannot be recycled in some regions. The aim of this paper was to evaluate an alternative for recycling discarded PET straps in concrete paving blocks. Fresh and hardened properties of the composite were tested for dosages containing 1%, 5% and 10% of shredded PET straps by total weight. Later, the environmental impacts of this recycling alternative were evaluated using the life cycle assessment (LCA) methodology. The increase of shredded PET straps content decreased slump, density and flexural strength of blocks, and a content of 5% of plastic had the lowest water absorption. All studied environmental impacts were reduced by increasing the amount of plastic content. Although shredded plastic straps could not improve the technological properties of concrete, except from water absorption, this recycling alternative could still be used to reduce environmental impacts of paving blocks production, substituting raw materials with up to 5% of plastic by weight. [ABSTRACT FROM AUTHOR]

This research proposes to include different percentages of recycled polypropylene (PP) fibers and polystyrene (PS) granules in the manufacture of concrete blocks. They are thermoplastic materials widely used in industry and are characterized by their lightness, their low thermal and electrical conductivity, and their low humidity absorption coefficient, factors that improve the efficiency of constructions. The results of this study show improvements in the mechanical behavior of the blocks with these plastic additives compared to the traditional ones, along with improvements in the structural behavior of the low (2-story) and medium-height (8-story) frames. [ABSTRACT FROM AUTHOR]

A comprehensive study of the radiological CNGS (CERN Neutrinos to Gran Sasso Experiment) environment characterization is presented. It comprises the evaluation of the residual dose rates of the most relevant standalone beam line equipment, such as the target and horn, as well as overall dose levels in the cavern before and after dismantling. Furthermore, the radionuclide inventories of the main objects to be dismantled were calculated by the Monte Carlo FLUKA code and ActiWiz. The latter is particularly important for transport and waste management. Moreover, we present benchmarking measurements of residual dose rates in the experimental cavern, staying in good agreement with simulation predictions. Additional measurements, as well as FLUKA and ActiWiz studies, allowed for assessing the concrete composition of the cavern's walls and floor and the shielding blocks. The resulting refined composition allowed for evaluating more precisely the radionuclide inventories and residual dose rates expected before and after the dismantling in the CNGS target area. This was particularly important for the evaluation of the dismantling cost and the substantial savings due to the reusage of the majority of the concrete blocks. Finally, contamination measurements in the accessible parts of the area also are included. All the results discussed are crucial for determining the requirements, planning, and costs of the CNGS dismantling. [ABSTRACT FROM AUTHOR]

This study delves into the environmental impact of concrete block manufacturing, focusing on embodied energy, CO2 emissions, and water consumption. The research addresses the pressing need to understand the ecological implications of concrete block production for sustainable development. We use a comprehensive life cycle assessment (LCA) methodology to assess embodied energy, CO2 emissions, and water consumption throughout the concrete block production lifecycle. The study draws upon primary data from industry sources and secondary data from research studies to ensure accuracy and reliability. Findings reveal that concrete block manufacturing demands significant energy, primarily attributed to cement and aggregate production and transportation. The process generates substantial CO2 emissions from limestone calcination during cement production. Water consumption is a critical concern during the curing and washing stages. The study explores diverse strategies and technologies aimed at mitigating the environmental impact. Implications of this research highlight the importance of adopting sustainable practices within the concrete block industry to address environmental impact. This study emphasizes the concrete block industry's potential to contribute to a greener and more sustainable future by implementing environmentally friendly measures. This study's comprehensive analysis and actionable recommendations aim to attract readers and stakeholders, encouraging further interest and investment in sustainable practices. [ABSTRACT FROM AUTHOR]

The degradation of the interlocked pavement depends on the defects, mainly in the bearing layer. This happens because the change in the load attenuation capacity of the concrete blocks modifies the state of stress imposed on the rest of the structure. In this sense, this paper aims to evaluate how defects in the covering of an interlocked pavement, in different severities, alter its service life. The results showed that the defects in the joints between the pieces have a greater influence on the reduction of the service life, the results for the analyzed pavement showed a reduction of the service life of up to 5 years. On the other hand, the damage of the blocks and the loss of useful height of contact between the pieces acting in isolation impair the structural capacity of the pavement, however for the analyzed pavement allow the structure to support the desing traffic. It also observed that the aggravation of the analyzed defects generates an overlap of effects that promote the increase of damage, having a more significant impact on the reduction of the pavement's service life. [ABSTRACT FROM AUTHOR]

Mineral fillers are known to affect the cracking properties of hot mix asphalt (HMA) significantly. Therefore, the aim of the study was to investigate the effects of filler concentration on the indirect tensile cracking indices of hot mix asphalt at an intermediate temperature. To make the test samples, the standard 100% limestone filler was substituted with the recycled fillers of hollow concrete block (HCB) powder and brick powder (BP), in three different concentrations (3%, 5%, and 7%). Optimal concentration levels resulted in superior mixes that could sustain pavement service life and environmental friendliness. Mixtures with 100 and 150 mm-diameter specimens were evaluated using the flexibility index (FI), crack tolerance index (CT index), fracture energy index (FEI), toughness index (TI), cracking resistance index (CRI), and fracture strain tolerance (FST) index from IDT test. The results indicate that filler concentrations influence the IDT indices significantly and that the 5% filler mixtures yielded reasonable testing results. The two specimen sizes were found to have moderate to strong correlation coefficient (R2) values for the same indices, supporting that both may be used interchangeably to assess cracking resistance in HMA. Thus, using 100 mm-diameter specimens may be used to minimise costs and material quantities. [ABSTRACT FROM AUTHOR]

This study focuses on evaluating the response of concrete block pavement (CBP) reinforced with rubberised oil palm shell (ROPS) layers when subjected to vehicular loads using laboratory experiments and finite element (FE) simulations. The key parameters considered in this study are the sand bed thickness, oil palm content in ROPS layers, embedment depth of ROPS layers, and vehicle velocity. The dynamic loads due to the vehicular movement were generated using a real-time road unevenness signal. Outcomes from the lab-scale 1g experiments and FE simulations were expressed as displacement and acceleration responses in the frequency domain. CBP sections with sand bed thicknesses of 10mm and 70mm were found to yield high surface deflection and acceleration values, both with and without ROPS reinforcements. CBPs reinforced with the ROPS layer having 20% OPS content demonstrate the best performance compared to ROPS layers made with 5% and 10% OPS contents. Further simulations show that the ROPS layers at an optimum embedment depth of 180mm from the surface in the CBP profile can significantly reduce the unacceptable levels of vibration. To this end, this preliminary research attempts the possible reengineering of oil palm shells and ascertains the suitability of ROPS reinforcements in stabilising CBP−soil systems. [ABSTRACT FROM AUTHOR]

This research investigates the impact of reduced graphene oxide (rGO) on the temperature gradient and associated stresses of mass mortar blocks. When the thermal stresses induced by the temperature gradient between the core of mass mortar or concrete blocks and their surfaces exceed the tensile strength of the concrete, cracking can occur. The measurements of temperature evolution at several locations in two mortar blocks with dimensions of 0.48 m x 0.41 m x 0.68 m are obtained from the literature. The first block was cast with a reference mix (REF) which contains only ordinary Portland cement, whereas the cement was replaced by 1.2% rGO for the other block. A finite element simulation of the two blocks was carried out and the measured temperature evolution was captured with a reasonable precision. Subsequently, numerical simulation was used to investigate the influence of rGO on the temperature rise and the associated potential of cracking in the mass mortar blocks with dimensions of 1 m x 1 m x 1 m and 2 m x 2 m x 2 m. It is noted that the rGO has a significant effect on reducing the the cracking indices of mass mortar blocks. [ABSTRACT FROM AUTHOR]

Unreinforced concrete block masonry (URM) walls are seismic vulnerable. Thus, this study examined the responses of URM walls strengthened using high ductile fiber-reinforced concrete (HDC) to assess the effectiveness of the proposed retrofitting technique. A reference specimen and five retrofitted specimens were tested based on the cyclic loading program; the strengthening configurations included the HDC strips or layers. The experimental results validated the effectiveness of the retrofitting techniques for enhancing the seismic performance of URM walls. The paper proposed the formulas to calculate the bearing capacity of each specimen corresponding to different failure modes, which is informative for engineering design. [ABSTRACT FROM AUTHOR]

This research aims to examine the mechanical characteristics and thermal performance of concrete masonry blocks made from clay waste bricks that have been crushed, used as coarse aggregates, and incorporated plastic bottles. A simulation of the heat transfer of blocks was also made using Finite Element Method. The study uses plastic bottles of 350 ml of volume and clay brick waste as a complete replacement for traditional aggregates to produce lightweight concrete. The blocks utilized in the study were 150 mm × 200 mm×400 mm in size. The blocks underwent testing for various properties such as water absorption, ultrasonic pulse velocity, density, compressive strength, and thermal conductivity to ASTM C140 standards. The incorporation of plastic bottles created 23% voids in the blocks for the density test, and the results revealed that the block's performance met the ASTM C129 standards for load-supporting blocks with regard to its capacity to absorb water (134.9 kg/m3), lightness, and strength (12MPa). Additionally, the study revealed a decrease in thermal conductivity by more than 50% compared to conventional concrete blocks without bottles; a result which was confirmed by the blocks' heat transfer simulation. In conclusion, based on the fact that the blocks studied met the mechanical standards for load-bearing masonry units, it is proposed that the construction sector consider incorporating these types of blocks in areas where heat insulation is necessary to reduce building energy consumption related to cooling. [ABSTRACT FROM AUTHOR]

In the aftermath of the deadly 2018 Anak Krakatau tsunami (Indonesia) and associated confusions over its modeling and generation mechanism, there has been an urgent need for further studies to improve our understanding of landslide-generated tsunamis. Two important factors in accurate modeling of landslide tsunamis are the wave period and the initial wave amplitude. Here, we apply a physical modeling approach and develop an empirical equation to predict the dominant wave period generated by solid-block subaerial landslide tsunamis. Fifty-one laboratory experiments are conducted at different water depths and using four different concrete blocks for the sliding masses. The results are consequently employed to derive a predictive equation for the wave period of solid-block subaerial landslide tsunamis. An innovation of this study is that we apply data from different scales (laboratory and field scales) to produce our predictive equation. For field data, the data from the 2018 Anak Krakatau event is used. We compared our predictive equation with other previously-published equations. To confirm the validity of our predictive equation, it is applied for the prediction of the wave period of an independent landslide tsunami event whose data was not used for the derivation of the equation. [ABSTRACT FROM AUTHOR]

Concrete is a highly versatile construction material thanks to its behavior and mechanical properties. However, little is known about improving its properties through including additives in its manufacture. Concrete also has drawbacks, such as brittleness, low ductility and poor flexural strength. This material is used in many parts of the structures and may be manufactured on site or prefabricated, e.g. in the form of blocks. Including steel and aluminum alloy fibers in concrete would improve the ductility and flexural strength. This study analyzed and compared the mechanical behavior of normal concrete blocks with others made with aggregates of steel and aluminum alloy fibers. Mechanical lab tests were carried out on blocks with five, four and three layers of fibers, taking into account the requirements of the Chilean Regulations. [ABSTRACT FROM AUTHOR]

Interlocking Concrete Block Pavement (ICBP) is a special type of pavement with a unique load spreading mechanism due to the discrete wearing layer. There is a lack of design procedure and design charts for the ICBP in India, as reported by the IRC SP 63 [2018. Guidelines for the use of interlocking concrete block pavement. New Delhi: Indian Road Congress] specification. The objective of the present study is to develop a design procedure for ICBP which complies Indian standards specification. The study also aimed to develop the deflection model and combined elastic modulus model for ICBP wearing layer considering the geometric properties of ICBP based on laboratory and numerical studies. The design procedure was then formulated considering the deflection of the pavement section and the rutting of the subgrade. The proposed design procedure was validated with the ICBP design section of ASCE58-10 [2010. Structural Design of Interlocking Concrete pavement for municipal streets and roadways. American Society of Civil Engineers] developed by ASCE (American Society of Civil Engineers) and ICPI (Interlocking Concrete Pavement Institute). The study finally arrived in developing a design chart and design software named NITT-BLOCKPAVE, which is programmed based on the proposed design procedure for the ICBP pavement section. [ABSTRACT FROM AUTHOR]

A nonlinear finite element (NLFE) model was developed to describe bond behavior between heat-damaged concrete and near-surface mounted (NSM) fiber-reinforced polymer (FRP) strips. The different components of near-end pullout specimens were represented using proper elements in ABAQUS software with the cohesive element adopted to consider bond behavior. The model is calibrated using data from two published experimental works, before its predictions were extrapolated to consider the effect of temperatures (23–550 °C), along with the effects of concrete strength (25–55 MPa), bond length (100–350 mm), spacing (50–200 mm) and fiber type of NSM CFRP strips. Elevated temperatures, in excess of 300 °C, caused a reduction in residual pullout force, yet an increase in bond ductility. The degradation in bond was more pronounced for specimens with higher-grade concrete and lower spacing between strips. Exposing concrete blocks to 450 °C and above undermined the contribution of NSM CFRP strips (100–350 mm) to bond strength. The type of composite had a minor (if any) impact upon bond behavior between heat-damaged concrete and FRP strips for temperatures higher than 300 °C. The NLFE cracking patterns indicated that bond failure mode in the pullout specimens is dictated by the spacing between strips with minimal impact of exposure temperature or bond length. [ABSTRACT FROM AUTHOR]

In developing countries, it is necessary to have appropriate transport infrastructure and industrial facilities that support the fluctuating loads from increased use over time. The in situ concrete block pavements (ISCBP) arise as a cost-effective alternative to the traditional solutions. Few studies that analyse the structural behaviour of ISCBP mention that it works like a flexible pavement. However, these studies are based on experience and results of surface deflections. To analyse the behaviour of ISCBP, two test sections were constructed, in which the vertical stresses, generated by mobile and impact loads (HWD) with different load levels, were measured in the granular base. The results were compared using a layered elastic analysis programme (MnLayer). Under the conditions of this study, the comparison between the measured vertical stresses and those estimated by the programme indicated that the ISCBP presented a linear elastic behaviour. Similar to a flexible pavement, ISCBP reached coefficients of determination (R2) in the order of 0.99 and biases that ranged from 11% to 48% when applying impact loads. Nevertheless, the modulus of the block layer demonstrated that it is dependent on thickness. [ABSTRACT FROM AUTHOR]

We subjected nine full-scale masonry infilled reinforced concrete frame specimens to quasi-static cyclic loading to critically review the methods for determining the damage state of masonry infill walls to develop reliable in-plane fragility functions. Among the three methods, the method based on maximum crack widths gave the smallest dispersion, whereas the skeleton curve-based methods generated excessive dispersions and the phenomena-based method was shown to be self-contradictory in certain circumstances. If the damage states were determined by maximum crack widths, neither the brick type nor the plaster had a significant influence on the fragility functions. [ABSTRACT FROM AUTHOR]

In this study, experiments are conducted to investigate the effect of wall-to-frame connectors on in-plane/out-of-plane (IP/OOP) behavior of the steel frames infilled with autoclave-cured aerated concrete (AAC) wall to find a reasonable connection type. Six infilled frames with different connection designs were tested. In specimens with V-shaped and T-shaped connectors, the OOP stability of the wall was maintained, the frame–wall interaction was ignored, and the wall remained intact up to 2.5% IP drift. They compensated the stiffness degradation and strength reduction of the frame after 2.5% drift. These two connectors can be used as prequalified connectors in the steel structures. [ABSTRACT FROM AUTHOR]

The purpose of the study was to use waste rice husk ash (RHA), residual ash generated at the rice husk fuelled clay brick kiln, for manufacturing paving blocks. Strength, durability, water quality of the paved surface run-off and microstructure of specimens were examined. Cement in paving blocks was partially replaced by five percentage of waste RHA: 0%, 5%, 10%, 15%, and 20% (by weight). At 10% waste RHA, paving block structure became denser than the conventional block, and 56-day compressive strength was improved by 18.1% and 26.5% for M15 (Grade 15) and M25 (Grade 25) blocks, respectively. Paving blocks with 10% waste RHA achieved splitting tensile strength and flexural strength greater than that of the conventional blocks. At all waste RHA levels, sulfate resistance was improved, water absorption was ranged 3–6% and British Pendulum Number was found to be higher than 45, satisfying the limits specified in standards. For the run-off, total suspended solids concentration was less than 6 mg/l, turbidity was ranged 2.15–3.57 NTU, conductivity was ranged 74.0–137.0 μs/cm and satisfied the limits in standards. This study concludes 10% of waste RHA without any pre-processing can be used as a cement replacement in paving blocks. [ABSTRACT FROM AUTHOR]

Shear stress behaviour is one of the predominant characteristics which influence the performance of Interlocking Concrete Block Pavement. The primary objective of the present study is to find the influence of bedding sand and jointing sand on the interface shear stress behaviour of Interlocking Paver Blocks (IPB) and bedding sand. The shear stress behaviour was studied using a large-scale direct shear test. Three grades of bedding sand were involved in the study. PLAXIS software was used to simulate the laboratory test results and the accuracy of the test results was statistically validated. In order to avoid tedious experimental studies, further analysis was executed using PLAXIS software. Eight gradations of jointing sand were analysed using numerical modelling to interpret its influence on the interface shear stress behaviour. The actual shear stress due to the traffic load for 50 million standard axles was estimated using IITPAVE software and the respective interface shear strength was calculated from the experimental results to ensure that the interface shear strength can resist the actual shear stress. Laboratory and numerical test results unveiled that the IPB when laid on Zone II bedding sand packed by Zone II>>2.36 jointing sand exhibited better interface shear stress behaviour. [ABSTRACT FROM AUTHOR]

Layered elastic theory is a familiar and commonly accepted framework for modelling and analysis of pavement systems. In actuality however, the suitability of the theory is challenged whenever the system includes a fragmented layer – which violates the inherent layer continuity assumption. This paper addressed the modelling challenge in these situations by introducing a fragmented layer into the accepted framework. A new formulation was proposed, based on the hypothesis that the thickness of the fragmented layer can be incorporated as part of its governing parameters. Doing so allowed for treating the fragmented layer as a new kind of interface. Subsequently, the work focused on formulation development and clear step-by-step presentation of new derived expressions applicable to the case of a stratified half-space containing a fragmented layer. Several synthetic cases were generated and interrogated to verify the correctness of underlying equations and to demonstrate capabilities. Based on this interrogation the proposed formulation is deemed rich of prospective utility, especially for modelling pavements surfaced with concrete paving blocks, pavement systems that contain cracked-and-seated (or rubblised) Portland cement concrete, and aged or rehabilitated pavement systems that contain fatigued (multi-fractured) asphalt concrete layers. [ABSTRACT FROM AUTHOR]

Industrial waste is an inevitable problem that is currently endured by most of the developing countries. Waste granite dust is one among the many detrimental industrial wastes originating from the granite manufacturing. The objective of the present study is to determine the optimum percentage of waste granite dust to be adopted in the manufacturing of Interlocking Concrete Block pavers (ICBP) by replacing sand with up to 30% waste granite dust. The mechanical properties such as water absorption, compressive strength, split tensile strength and flexural strength are analysed along with other Non-destructive testing methods like ultrasonic pulse velocity test. Frictional behaviour is examined using skid resistance test and abrasion test. Microstructural studies are carried out using X-ray fluorescence (XRF), X-ray powder diffraction (XRD), scanning electron microscope (SEM) and energy-dispersive analysis X-Ray (EDAX) to validate the test results. The optimum percentage of granite dust is concluded as 25%, as inferred from the test results. Statistical analysis is executed to review its significance. Economical study affirms a cost saving of 5.5% per cubic metre of ICBP production. The inherent advantages such as strength enhancement, eco-friendliness and cost-effectiveness of the waste granite dust make it an acceptable and sustainable alternate construction material. [ABSTRACT FROM AUTHOR]

In Mexico, there are efforts to recover earth-based construction systems, mainly those that improve the comfort characteristics consisting of a thermal sensation different from that of the environment. One of the questions derives from the reason why, at high ambient temperatures, earth houses tend to have a much lower temperature inside while, at very low temperatures, indoor temperatures are higher. This paper analyzes a type of housing present in Tamaulipas, Mexico, characterized by adobe walls and palm roofs. From a specific solution of the transport equations considering the heat capacity of the material and the coefficient of thermal conductivity, it is shown that the heat transfer of a homogeneous material in housing is dominated by these two properties, which justifies the present architectural design and the paradigm of a better comfort of earthen dwellings concerning industrialized materials such as the concrete block, we also show the energy efficiency according to NOM-020ENER-2011. [ABSTRACT FROM AUTHOR]

The present paper deals with the long-term experimental study focusing on the properties of concrete mixtures with the addition of ceramic powder, which originate during the hollow brick production. The used ceramic powder was applied as Portland cement replacement up to 30 wt.%. The properties of concrete were evaluated in terms of fresh mixture parameters, mechanical, permeability and durability properties based on the accelerated testing. The progress of the pozzolanic reaction was monitored using thermal analysis. Higher dosage of ceramic powder caused a significant loss of workability and an increase of permeability, which were declared on the results of carbonation test and freeze–thaw cycling. However, a mixture with 25 wt.% replacement exhibited values similar to the control mixture after 3 years. The production of vibro-pressed concrete pavement element was selected for industrial testing due to the reduced workability. However, only 15 wt.% replacement was applied for the operational tests, which were evaluated in terms of split strength after 5 days and freeze–thaw cycling after 28 days. Industrially produced specimens exhibited similar or higher values of studied parameters in comparison to the control mixture. Long-term mechanical tests and freeze–thaw cycling confirmed great practical potential of ceramic powder for these type of elements. [ABSTRACT FROM AUTHOR]

The increase in the production of armaments following the outbreak of the First World War led to an expansion of existing factories and the building of new manufacturing facilities. Alongside this rapid growth was a need for additional accommodation for the workers. Due to the shortage of both traditional building materials and tradesmen, many of these developments used non-traditional materials, and several housing estates were built using concrete blocks or precast concrete systems. Despite being over 100 years old, most of these estates remain, and in many cases are still highly regarded. As with many housing estates for industrial concerns, they were built to high standards with modern facilities to attract workers to the area. The research presented in this article is based to a significant extent on contemporary reports and descriptions, coupled with visits to a selection of housing estates of the period. [ABSTRACT FROM AUTHOR]

This research aims to estimate the operational energy (OE) savings of a full-scale building, made of lime hemp concrete (LHC) with alternative binders partly replacing lime, compared to buildings made of conventional materials, e.g. Autoclaved Aerated Concrete (AAC), Hollow Concrete Blocks (HCB), and Expanded Polystyrene (ESP). The thermal performance of small size (1 m × 1 m) different materials test cells was experimentally studied. Experimental results were compared to simulated values obtained by EnergyPlus. Monitored and simulated indoor temperatures were found to be in good agreement. Subsequently, the thermal performance and energy consumption of full-scale buildings (10 m × 10 m × 2.9 m) were simulated by EnergyPlus with a great degree of confidence. In up-scaled building simulations, LHC presented the best thermal performance and consequently the lowest energy consumption, reaching ∼7 kWh/m2/year, nearly Zero Energy Building standards, 90% lower as compared to HCB which obtained the highest energy consumption. Dynamic external window shading was shown to have a significant impact on cooling energy savings. This research clearly shows the high potential of using LHC with alternative binders as a partial replacement for lime, as it has advantages in terms of energy savings, and their equivalent CO2 emissions. [ABSTRACT FROM AUTHOR]

Previous research studies have shown that abutment scour makes a major contribution to bridge failures. Protecting bridges against scour is, therefore, a priority need. For existing bridges, armouring methods, such as riprap, have a wide application. In the areas where providing stones is expensive, concrete blocks or similar techniques are often used. In the present study, the application of the Six Legged Concrete (SLC) elements was experimentally investigated. The SLC elements were placed in three different densities (open, medium and dense) at three different placement depths (h/l = 0, 0.5 and 1; where h is the element installation height above the bed and l is element height). Each alternative was tested under different flow conditions for a wing-wall abutment. In general, the results showed that the SLC elements can considerably reduce the scour under different flow conditions. In an optimal arrangement, the elements reduced the scour depth at abutment nose up to 100%. The maximum reduction of scour depth was obtained when the SLC elements were placed densely on the bed (h/l = 1). [ABSTRACT FROM AUTHOR]

There has been a longstanding concern among construction scholars and practitioners in classifying construction innovations, whether as "incremental" or "radical," "technological" or "organizational," "product" or "process". In this paper we extend this interest in classification to examine what classification work accomplishes within construction innovation practices. Instead of addressing the validity of innovation categories as objective representations we explore how innovations are classified within everyday interactions that shape how they proliferate. Our approach is informed by socio-material theories of classification, communication and innovation, particularly those from Actor-Network Theory (ANT) and Ventriloquial Analysis (VA). Empirically, our approach is developed through an analysis of how a single innovation – a large format concrete block – was classified within a single warranty approval meeting as it entered the UK housing market. Our analysis explains how such classification work is dynamically constituted by formal and informal classificatory acts that involve displacements of human agency that shape how construction innovations proliferate. Classification work is thus shown to make a vital difference to how construction innovation is accomplished and can be understood. [ABSTRACT FROM AUTHOR]

During the last decades, environmental sustainability has acquired growing importance in different productive sectors. The construction sector, aware of its environmental impacts, searches for mitigation within both processes and inputs. One of these mitigation strategies is the recycling of construction and demolition waste within the production chain. This paper deals with the proposition and application of a systematic decision-making tool in the context of the construction industry. The proposed procedure introduces a tool for Sustainable New Product Development using Quality Function Deployment to analyse the use of recycled aggregate for making concrete blocks in a multivariate context. That tool allows requirements identification and prioritisation considering the perspectives of both customers and developers, as well as standards and environmental aspects. Some results of a real case application are presented, and the benefits and potential barriers related to its adoption are discussed. These results contributed to the identification of trade-offs associated with the challenge of comparing alternative construction materials. It was also possible to identify that the use of recycled materials does not necessarily ensure that a product is more environmentally friendly than others. [ABSTRACT FROM AUTHOR]

Redirecting the actual construction industry, which is one of the major sources of global pollution, is relevant to achieve green innovation efficiency. Researching on the potentials of wood species can lead to propose alternatives that allow reducing/reinventing conventional building materials and systems. This investigation aims to determine, evaluate and analyze the biomechanical/structural properties and performances of lightweight sandwich-like composite biopanels made of bamboo, melina and balsa. A total of 92 samples were experimentally tested under compression, bending, shear, tension, density, moisture content, glue and ply-delamination. The experimental data were validated and compensated through 82 finite element analyses. The acquired results were compared with equivalent sections of conventional materials in terms of strength, rigidity, structural behavior and mechanical efficiency. E.g. the results show the biopanels are up to two and three times more mechanically resistant than solid wall bricks and concrete block walls, respectively; and, up to nine times higher in terms of mechanical efficiency than steel. The results from the biomechanical analyses confirm the practical utilization of the wall biopanels into nonconventional building projects even as structural elements; most important, the implementation of the proposed wall biopanels into actual building systems would significantly reduce fatalities and destroyed dwellings during seismic and windy events due to its remarkable flexibility, strength and ductility. [ABSTRACT FROM AUTHOR]

Inspection of critical social infrastructures, which are mainly made of concrete, is a pressing issue. Weakly supervised methods are interesting for such critical tasks because they allow a unique mix of human involvement and automation. However, humans can make mistakes, resulting in the system being misled. In the present paper is proposed a framework for weakly supervised defect detection in concrete structures involving a consensus between several humans providing weak supervision. This allows to compensate for the shortcomings of each individual human and, therefore, yield better performance along with robustness to erroneous weak supervision. Experiments conducted with concrete test blocks in laboratory conditions showed the effectiveness of our proposed method. [ABSTRACT FROM AUTHOR]

In this study hollow blocks were produced using coconut shell (CS) as coarse aggregate. For comparison, hollow blocks were also produced with conventional concrete (CC). Mixes were produced both in field and laboratory. Both conventional and CS mixes satisfied the minimum strength required as per IS 2185 (Part 1): 1987. Hollow blocks were tested for their basic properties, shrinkage characteristics, durability properties and bond strength. CS plays a significant role in reducing the shrinkage cracks in the concrete compared with CC constituents. Mixes developed in laboratory displayed better durability properties compared with mixes used in field. Water absorption of hollow blocks was well within the allowable limit of 20%. The experimental bond stresses at 28 days were more than the theoretical bond stress calculated as per BS 8110. This study infers that the use of CS as a potential construction material in the production of hollow blocks is feasible. [ABSTRACT FROM AUTHOR]

Permeable pavements are engineered to temporarily store water to reduce flooding during rainfall events. Permeable pavements are distinguished primarily based on their surface materials which can vary from concrete, asphalt, clay brick, concrete pavers or plastic grids. This paper examined the effect of lightweight carbon-negative aggregates (CNA) on the behaviour of concrete intended for use as solid concrete block pavers in permeable pavements. Performance indicators targeted compressive strength, splitting tensile strength, density and water absorption. CNA were produced and sourced from manufacturing firm Carbon8 Systems in Kent U.K which applies patented accelerated carbonation technology to solidify incinerated ash into useful eco-friendly aggregates. The methodology involved substituting natural aggregates (NA) by mass, with CNA at percentages varying from 0 to 100. A scanning electron microscope was used to examine the aggregate–mortar interface. Both the compressive and tensile strengths decreased exponentially with the addition of CNA. Average 28-day compressive and splitting tensile strengths ranged from 69 MPa (10,000 PSI) to 18 MPa (2600 PSI) and 3.84 MPa (560 PSI) to 1.23 MPa (178 PSI) respectively. Density values decreased linearly with the addtion of CNA with average values ranging from 2200–2600 kg/m3. ⁠Conversely, water absorption increased with increases in CNA with average values ranging from 1.66% to 9.17%. Depending on the loading requirements, CNA can replace NA in solid permeable pavement blocks by up to 100%. [ABSTRACT FROM AUTHOR]

Many buildings of the 1940s to the 1970s are decorated with monumental façade artworks. These murals, mosaics, and integral sculptural reliefs sometimes gain in cultural value even if the buildings on which they are installed do not. When a building that supports an artwork is designated for demolition, artworks whose scale and installation never accounted for future repositioning are endangered. Frequently, owners or developers are loath to consider any option besides demolishing the artworks along with the building, due to cost, or a fear that rescuing them will hold up construction. The result is great loss of iconic artworks. This paper will demonstrate conservation methods for dismantling, removing, and relocating mid-twentieth century modern architectural artworks. Case studies will include the relocation of a monumental 1963 mosaic at Houston Methodist Hospital; dismantling a 1961 brick/concrete block mural on a Miami, Florida facade; and the removal and relocation of a Millard Sheets mural in Santa Monica, California. The authors will discuss strategic approaches used to help clients understand that these endeavours are possible, as well as specific methodologies, challenges, pitfalls, budgetary considerations, and best practices for achieving results. [ABSTRACT FROM AUTHOR]

Permeable Pavement (PP) represents a good solution to solve stormwater management problems. In this way, the potential removal efficiency of a PP in treating dissolved metals was assessed by performing a monitoring campaign at a lab-scale system. Based on literature experiences, different relatively high-level concentrations of copper and zinc were applied during eight different synthetic rainfall events. Results have shown that the removal rates of Cu and Zn of the lab-scale system range from 85% to 92% and from 65% to 82%, respectively. In addition, batch experiments were carried out on each construction material of the PP highlighting that, among the materials tested, only concrete blocks presented the potential to adsorb the investigated metals. Results confirmed that the adsorption capacity of the blocks is higher in adsorbing Cu (70–90%) than Zn (69–75%). Results from LCA analysis have shown overall minimal long-term, indirect and cumulative impact. [ABSTRACT FROM AUTHOR]

While precast cement mortar block has often been used in modular pavement, precast HMA (Hot Mix Asphalt) block has the advantages of flexible behaviour, no curing and recycling, etc. In this project, the mechanical characteristics of the precast HMA block were evaluated by comparing with precast cement mortar block. The objective of this project was to develop a method for the design of precast HMA block and the evaluation of its mechanical characteristics. The research contents include proportion design and preparation of precast HMA block, mechanical test of precast HMA block, comparative analysis between precast HMA block and precast cement mortar block. Through analysis on the mechanical characteristics of precast HMA block with non-reinforced and reinforced, the research results have indicated that the bending strength of precast HMA block decreases gradually with the increase of aggregate diameter. The comparative results have further indicated that the bending strength of precast HMA block can match the strength of the precast cement mortar block and that it can be applied in modular asphalt pavement. The precast HMA block has provided a feasible technology in modular pavement option. [ABSTRACT FROM AUTHOR]

Policy makers in India have realized the importance of facility for pedestrians and non- motorized vehicles in an urban infrastructure setup. This has resulted in increased utilization of construction materials like Portland cement and crushed stone, which are not environmentally friendly and sustainable. The current study presents the development of paver blocks for pedestrian facility using different wastes. Geopolymer concrete was synthesized by fly ash and recycled asphalt pavement aggregates for making of paver blocks. Paver blocks were produced in laboratory with recycled asphalt pavement aggregate replacement levels of 0%, 20%, 40%, 60% and 80% by weight of virgin coarse and fine aggregates. The developed paver blocks were tested for dimensions and tolerances, water absorption, compressive strength and abrasion resistance as per IS15658:2006 standard. The results of the laboratory study show that recycled asphalt pavement aggregates can be introduced into geopolymer matrix to produce paver blocks of desirable quality. Furthermore, its use in pedestrian facilities provides a new avenue for managing the excessive waste, which otherwise goes in landfills, incurring loss to the paving industry. Therefore, the proposed method can help decision makers to effectively utilize recycled asphalt pavement in paving industry with environment-friendly approach. [ABSTRACT FROM AUTHOR]

This paper investigates the properties of concrete block made from industrial waste materials. Two by-products, calcium carbide residue (CR) and bagasse ash (BA), were combined and used as a substitute binder for Portland cement, and 100% recycled concrete aggregate (RCA) was used to replace natural aggregate in making interlocking concrete paving block. The results showed that the densities of the concrete blocks with unmodified CR and BA as a binder were decreased, moreover, their water absorptions were higher than those of concrete blocks with high fineness of binder. The compressive strength of some concrete block can be sufficiently high to meet the requirement for interlocking concrete paving block in accordance with Thai Industrial Standard (TIS 827), which is higher than 40.0 MPa at the testing age of not less than 7 days. The abrasion resistance of concrete block is likely to be decreased compared to normal concrete due to the RCA in the mixture; however, the abrasion resistance can be improved by increasing the fineness of binder. These remarkable results indicate that CR, BA and RCA in suitably mixed proportions can be used as a good choice for an alternative material to make environmentally friendly interlocking concrete paving block. [ABSTRACT FROM AUTHOR]

An experimental study was completed on the behavior on post-installed bonded anchors in ultra-high performance fiber reinforced concrete with a compressive strength higher than 150 MPa. The aim was to analyze the failure mechanisms in static pullout tests. The diameter of the tested anchors was 12 mm and the studied parameters were the embedment depth, the edge distance and the state of cracking of the concrete block. In case of tests without edge effect in uncracked concrete, a combined pullout and concrete cone failure occurred for an embedment depth lower than 60 mm. The recorded mean bond stress was 32.5 MPa for uncracked concrete and 16.3 MPa for cracked concrete with a crack width of approximately 1 mm. A splitting failure was observed for shallow embedment and for edge distances lower than 60 mm. For this tested special anchor system, the increase in tensile strength provided by the metallic fibers enhances the tensile behavior of anchors in comparison to normal strength concrete. It is necessary to adapt the design codes developed for normal strength concrete in order to have more accurate and reliable prediction methods. [ABSTRACT FROM AUTHOR]

Bond behavior between corrosion damaged reinforced concrete and carbon fiber reinforced concrete polymer (CFRP) sheets was experimentally investigated. Forty ordinary strength concrete blocks (150 × 150 × 200 mm) were reinforced at one side across the 200-mm-dimension using three conventional ϕ12 mm steel bars at a spacing of (30, 40, and 50 mm) at a concrete clear cover of 15 mm. Thirty blocks were subjected to a cyclic treatment in 3% chloride solution until corrosion initiated and resulted in three different global cracking widths of up to 0.90 mm. Both control and corrosion damaged blocks were attached to CFRP sheets over their steel reinforced zone at bond lengths and widths ranging from (90 to 150 mm) and (50 to 150 mm), respectively, with CFRP bond length-to-bar spacing ratio kept constant at 1/3. Near-end pull-off tests were carried out using a special setup, mounted on a Universal Testing machine. Corrosion cracking caused significant reductions in bond strength, and slippage at ultimate stress at (41 and 68%), respectively. Other bond characteristics such as stress at first slippage, and bond stiffness and toughness were reduced, as well, by as high as (83, 44 and 67%) of those of control specimens, respectively. Corrosion cracks were more detrimental for smaller bond length and width values; especially after first and second corrosion stages, where bond failure was categorized by concrete skin peeling-off. [ABSTRACT FROM PUBLISHER]

Using wedge-shaped concrete blocks (WSCB) to protect earth dams against overtopping has received much attention in recent years. The aim of this study is to assess the pattern of the infiltrated flow through the WSCBs system into the downstream shell of the earth dam. Moreover, its effects on the downstream slope stability are investigated using the finite-element analysis. A typical zoned earth overflow dam with the WSCB spillway is modelled. For this case study, the effects of depth and duration of overtopping as well as the permeability coefficient of the shell materials on the water infiltration pattern and the downstream safety factor are studied. The results show that if the permeability coefficient of shell materials is more than 10−3 cm/s, even for overflow with shallow depths, the infiltration rate and the extent of the saturated region will rapidly increase. Consequently, the safety factors will significantly decrease for such cases. However, if the materials with permeability coefficient less than 10−4 cm/s are chosen for the shell, using this type of spillway would not endanger the stability of the downstream slope. [ABSTRACT FROM PUBLISHER]

Armor is a pavement made of erosion-resistant materials like a stone or concrete that is constructed to protect breakwater, coasts, and other coastal line features against erosion. These armors are a kind of protective layer made of stone or concrete, used in breakwater constructions or coastal lines, arrayed with specific regular or irregular pattern on the breakwater or the coast. The antifer concrete blocks have almost cubic form, often changed into frustum by adding inclined plates to their sides. One of the most important advantages of these armors is their diversified regular and irregular placement patterns. In this study, using the physical modeling and different tests, the stability level of antifer concrete blocks was evaluated considering the decrease of the armor weight. Results of this study show that by a 10% decrease in the block weight, the failure graph slope is increased and the damage is intensified. [ABSTRACT FROM PUBLISHER]

In order to verify the feasibility and effectiveness of the sensor used in complex concrete materials, an innovative application of ultrasonic phased array detection for a concrete structure was investigated. Comparing with the traditional piezoelectric composites, orthotropic piezoelectric composite material (OPCM) can be used as transducers in damage detection show clear advantages because of their high sensitivity and directivity along the polarization direction. A low frequency ultrasonic phased array transducer consisting of 16 OPCM elements is studied. The optimal array parameters, such as the phased array element interval, the array element width, and number of elements, are obtained by studying the total displacement changes as various parameters change at the focus point in the concrete structure. This configuration allowed the variation and control of the wave field directivity in the concrete structure during the measurements. The measurements were taken on concrete specimens using a precise time-delay device. The experimental measurements were compared to theoretical calculations to investigate the influence of different array element parameters. The results show that an OPCM phased array transducer can be used to detect damage in a concrete block. [ABSTRACT FROM AUTHOR]

In recent years, concrete block (CB) pavements have become a favourite alternative to asphalt pavements, mainly in intra-urban regions due to their architectural design possibilities. Unfortunately, this trend is restrained by a lack of adequate design methods to assess the load capacity and durability of such pavements. Especially, the mechanical performance of the vertical joints between CBs is often not depicted realistically enough. For this reason, in this work three new experiments are proposed to determine the mechanical behaviour of the joints between the CBs, and thus the load transmission capability of different joint formations. Mechanical models and the corresponding material parameters to describe the joint behaviour are identified from the experimental results. Finally, performance optimisation of block pavements with respect to their jointing behaviour should become possible. [ABSTRACT FROM AUTHOR]

This paper presents experimental studies on the behaviour of a thin layer polymer mortared concrete masonry under combined shear–compression. Thirty thin layer mortared concrete masonry panels with five bed joint orientations were constructed and tested under vertical compression to generate a wide range of compression to shear ratios from zero to infinity at each of the bed joints of the panels. The strength and deformation characteristics are discussed in this paper. Unlike the conventional 10 mm thick cement mortared masonry, the thin layer polymer mortared masonry failed in a combined mechanism involving both the block and the mortar in some combination of shear–compression; however, similar to the conventional masonry, its strength and deformation were affected by the orientation of the bed joint to the direction of the applied loading. This paper reports a comparative study of the experimental results with a number of shear–compression tests on varied masonry systems reported in the literature; the thin layer mortared concrete masonry is shown trending towards isotropic behaviour compared to conventional masonry, which is distinctly orthotropic. [ABSTRACT FROM AUTHOR]

The Charles Bridge is the oldest, still-standing gothic bridge that crosses the Vltava River in Prague and up to now has belonged among the most sought-after historical monuments in the Czech Republic. The bridge has been repeatedly damaged due to floods and has been repaired several times. In the reconstructions, damaged sandstone blocks were substituted in facing. This experimental study focused on nonlinear ultrasonic spectroscopy for testing stone blocks that were extracted from the historical bridge structure. The objective of these experiments was verifying whether the methods can be applied to evaluating the internal structure of blocks, which are built-in in the structure in situ. Intact-structure blocks, blocks that had been repaired in the past, and damaged-structure blocks were measured. Two methods of nonlinear ultrasonic spectroscopy were applied—the method with single harmonic ultrasonic signal and with two harmonic ultrasonic signals. Measurement results of both applied methods proved resulting parameters correlation with block structure integrity quality. [ABSTRACT FROM PUBLISHER]

The aim of this study was to investigate laboratory performance of crumb rubber concrete block pavement (CBP). Four different paving blocks containing 0 (control), 10, 20 and 30% rubber by total sand volume with compressive strength ranging between 23 and 64 MPa were used. The test pavement was subjected to 10,000 cycles of load repetition under a single truck wheel via a tyre inflated to 600 kPa. Nine measurements of pavement deformation and joint width were made at various stages of trafficking. Additional tests, including pull-out, skid resistances and falling weight test, were then carried out. Overall, crumb rubber CBP is observed to show inferior performance than the conventional CBP in rut, deformation, skid resistance and shear resistance but showed a great improvement in toughness. Thus, all paving blocks studied in this project have a great potential to be used according to traffic volume and types of applications. [ABSTRACT FROM AUTHOR]

The effect of varying runoff on a clogged permeable surface was analysed using a specifically designed laboratory rig consisting of a variable gradient testing frame, a rain simulator and water collecting chambers. The results indicate that the apparatus can be used successfully to test the runoff resistance of concrete blocks in permeable surfaces. The results indicate that a surface at 2% gradient that is clogged with crushed construction debris still permits significant levels of infiltration. [ABSTRACT FROM AUTHOR]

Field studies have suggested that wave velocities through concrete samples decrease with increasing damage. However, to date there has been no replication of this effect in a laboratory setting allowing for a controlled experiment to quantify this effect. The primary objective was to see how the exposure of concrete to sulfate solutions related to surface-wave velocity and through-wave velocity. The impact–echo method and the ultrasonic pulse velocity test were used to quantify these relationships, respectively. Laboratory research focused on correlating nondestructive test (NDT) data with destructive test results from field-sized concrete samples exposed to continuous sulfate attack over time. The intent was to evaluate the capabilities of the NDT techniques in identifying and quantifying damage due to sulfate attack. Prior research has shown that tension testing tends to be far more sensitive than compression testing to such damage. As a result, it was expected, and confirmed, that stress wave velocities from the two NDT techniques correlate better with tensile strength than with compressive strength. [ABSTRACT FROM AUTHOR]

A drawing of three-dimensional blocks is presented.