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During the purification of zinc metal, the slag waste generated causes various problems such as environmental pollution and storage. It is necessary to evaluate these wastes in different areas for effective management. In this study, the effect of slag from zinc production facilities on the mechanical properties of mortars obtained by substituting slag for fly ash in geopolymers at a replacement rate of 10-50% by weight was evaluated. Mortar mixtures were subjected to various tests including workability, flexural strength, compressive strength, water-absorption, and void ratio. Mortar mixtures containing NaOH with a liquid/binder ratio 0.40 were subjected to thermal curing at 90°C for 24 hours. Flexural and compressive strength tests were conducted on 7 and 28 days of samples. As a result of the tests, it was determined that the flexural strengths of mortars produced with slag ranged from 3.0 MPa to 5.8 MPa after 28 days, while the compressive strengths ranged from 28.2 MPa to 45 MPa. Mortar mixtures containing slag achieved 48-136% higher compressive strength values than the control mixture containing fly ash (19MPa). High-temperature tests (400, 600, 800°C) revealed that mortar mixtures containing up to 30% slag achieved higher flexural and compressive strengths than the control. As the amount of slag in the mortar increased, water absorption and void ratios also increased. These results indicate that slag waste can enhance the mechanical performance of geopolymers. [ABSTRACT FROM AUTHOR]

The construction industry is recognized for its high consumption of natural resources, resulting in significant environmental impacts. Given this reality, it is essential to seek new methods and solutions that minimize the impact of this activity on the environment. An innovative approach consists of using pigments derived from acid mine drainage (AMD) as a sustainable alternative in the production of mortar for decorative façade cladding. In this context, the main objective of this paper was to evaluate the physical/mechanical properties of decorative mortars developed by partially replacing natural sand with pigment from acid mine drainage. Initially, the pigment (yellow) was produced, characterized, and compared with a commercial pigment. Sequentially, decorative mortars were developed with different pigment concentrations (0%, 2%, 4%, and 6%). The mortars were subjected to compressive strength, flexural tensile strength, shrinkage, loss of mass, and colorimetry tests. The results showed that compressive strength, flexural tensile strength, weight loss, and dimensional variation were significantly affected by the partial addition of pigment to replace natural aggregate. In other words, there was a decrease in strength and an increase in mass loss and expansion of the mortars. However, the main factor influencing these variables was the greater amount of water added in the higher substitution cases. The addition of water was necessary to keep the consistency constant. A possible solution to maintain the same amount of water and avoid negative effects on the mortar properties would be to use additives in the mortar formulation in future work. Therefore, this research contributes to the search for more sustainable solutions in civil construction, exploring the use of pigments from AMD as a viable alternative to reduce the environmental impacts associated with this industry. [ABSTRACT FROM AUTHOR]

The trade e off between protection and weight is a constant consideration when designing a portable protective solution. Greater mobility is a desirable attribute and protection must therefore adapt, prompting a demand for lightweight, simple to construct, low-cost and effective ballistic protection systems. High strength and ductility, wave spreading capability and good energy absorption are key properties for ballistic protection. Four materials, polycarbonate, Kevlar®-epoxy, polyurethane foam, and aluminium alloy, possess these properties and were selected for analysis by numerical simulation. Multilayered configurations were proven to be an optimal solution, by exploiting the advantages of each material without having large penalties of mass and cost. Numerical modelling using ANSYS AUTODYN® is used to simulate monolithic and multi-layered target configurations, to obtain the penetration mitigation performance. The results are analysed to select configurations based on different requirements, such as lowest cost, lowest mass, best performance, and optimal configuration which balanced the three key parameters mentioned. The optimal configuration of Aluminium, Kevlar-Epoxy, Polyurethane, and Polycarbonate has layers with thickness of 7, 3, 38, 2 mm respectively with a total mass of 7.97 kg, total cost of $39.86 and penetration of 29.34% (14.67 mm). Polynomial relationships between performance and mass/cost are also determined. [ABSTRACT FROM AUTHOR]

The aim of this study is to enhance the value and utilization of red mud generated in the Bayer process by preparing composite cement mortars. The effects of two different types of Bayer red mud with varying physical and chemical characteristics on the fluidity, mechanical strength, mineral composition, and microstructure of the composite cement mortar were systematically evaluated. The results showed that the optimal addition of red mud A was 10 wt%, while it was 20 wt% for red mud B. The mechanical properties of the composite cement mortar met the standards for P·O42.5 cement. Furthermore, the composite mortar with the addition of red mud B showed higher flexural and compressive strengths compared to the composite mortar with red mud A. This improvement is attributed to the smaller particle size of red mud B, which filled the micro-pores and increased the compactness of the cement stone, as well as its higher content of Na2O, K2O, and other free alkalis, which resulted in more obvious alkali activation, accelerating the hydration of the active minerals in the slurry. [ABSTRACT FROM AUTHOR]

This study focused on the application of nano-/micro-sized fibers obtained from pyrolysis of Santa Maria feverfew (biochar) in cement mortars. The biochar was added in amounts of 0, 0.05 and 0.1 percent by mass of cement. The mechanical characteristics were determined after 3 and 7 days and matched with those of the control samples. The compressive strength remained unchanged with the biochar addition, whereas the flexural strength increased. Biochar is a carbon-rich material, and its use in building materials leads to carbon sequestration, which is in accordance with the sustainable development goals of the UNO. [ABSTRACT FROM AUTHOR]

This paper evaluated the behavioural performance to coating mortar water with rubberized tyres. #0.60 mm and #1.19 mm grain sizes have been used with the incorporation of 10 and 20% (in volume), replacing the small units. The methodology has elapsed with capillary and drying tests; humidification and drying procedures with mass control, infrared thermography and measurement of humidity. The results indicated that in capillarity and drying the trace A20F (#0.60 mm particle size and incorporation of 20%) had have a low absorption rate and helped in the process of water disposal. In the humidification and drying process, both active as well as passive, the rubber possibly blocks the pores of mass, for the grain traits size #0.60 mm (A10F and primarily A20F) have proven easy to lose water, suggesting that the majority of water absorbed would be concentrated on the surface part of the composite. [ABSTRACT FROM AUTHOR]

The tower at Lublin Castle, known as the donjon, is the only monument of Romanesque art on the eastern side of the Vistula River. The cylindrical, brick building is part of the Lublin Castle complex. During contemporary restoration work, the 13th-century walls were uncovered, making it possible to retrieve the original materials. The article presents the mineralogical, chemical and granulometric characteristics. The analytical methodology included: qualitative mineralogical analysis of the whole sample by X-ray diffraction (XRD); morphological studies with elemental evaluation and microanalysis of the binder by scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDS). Residue determination of hydrochloric acid-insoluble parts and their granulometric analysis were performed. This methodology enabled to determine the composition of the mortars. It was found that the tested mortars have a similar mineralogical structure, but slightly differ in the proportion of individual components, primarily aggregate fractions. The samples consist mainly of quartz, calcite, and silicates. Moreover, the lime binder of the mortars was shown to be microcrystalline in nature. The aggregate used in historical mortars predominantly consisted of quartz sand and minerals of the feldspar and silicate group. The condition of the mortars requires conservation interventions. The performed characterization of the historic mortars was important for designing compatible restoration mortars. [ABSTRACT FROM AUTHOR]

The findings from the investigation conducted, to compare the structural performance of concrete containing treated (TOPEFB) and untreated Empty Oil Palm Fruit Bunch (OPEFB) fibres are presented in this paper. For the TOPEFB fibres, the dried fibres were treated with 0.2% NAOH solution following the procedures of ap-propriate authority. The structural parameters investigated were consistencies, setting times, densities, com-pressive and tensile strengths of concrete incorporating TOPEFB and OPEFB fibres in the mix. The addition of fibres was limited to 1.20% by weight of cement in the concrete. The interval of addition was 0.2%. The results showed that (i) the setting times of mortars containing TOPEFB fibres were higher than that of mortars with OPEFB fibres, (ii) concrete specimens containing TOPEFB fibres are more workable that concrete specimens with OPEFB fibres, (iii) densities of concrete specimens containing OPEFB fibres were in the range for normal concrete applications while the densities for specimens with TOPEFB developed densities that fell in the heavy weight concrete classification, (iv) concrete specimens containing TOPEFB fibres developed higher compressive strengths than specimens with OPEFB fibres and (v) tensile strengths of concrete specimens containing TOPEFB fibres were higher than specimens with OPEFB fibres by at least 59.04%. The overall conclusion from the findings of this study is that concrete specimens containing TOPEFB fibres have superior structural properties than specimens with OPEFB fibres. [ABSTRACT FROM AUTHOR]

As natural resources of sand and fine material used in the concrete industry are becoming more scarce, crushed materials are being used to a greater extent. Shape and texture of machine crushed materials differ from aggregates naturally ground, layered and sorted under the course of millions of years. It is assumed that crushed aggregates are more angular and of less smooth texture than natural aggregates, which will affect the flow behaviour of a suspension containing crushed material. In the mix design process of cementitous suspensions, an adequate rheology of the micro mortar (all constituents in the concrete being able to pass a 0.125 mm sieve, including the cement) is crucial. In this paper, the shape of fine particles is linked to the micro mortar plastic viscosity of the filler suspension including cement. The plastic viscosity here serves as an important quality assessment of the filler, since the micro mortar workability features are vital for the final mix design quality of the concrete workability. [ABSTRACT FROM AUTHOR]

Low calcium fly ash is used as the main material in the mixture and the crumb rubber was used in replacing fine aggregates in geopolymer mortar. Sodium hydroxide (NaOH) and sodium silicate (Na2SiO3° which were high alkaline solution were incorporated as the alkaline solution. The fly ash reacted with the alkaline solution forming alumino-silicate gel that binds the aggregate to produce a geopolymer mortar. The loading of crumb rubber in the fly ash based geopolymer mortar was set at 0% (CRGM-0), 5% (CRGM-5), 10% (CRGM-10), 15% (CRGM-15), and 20% (CRGM-20), respectively. NaOH solution (12M) and Na2SiO3 solution ratio is set constant at 2.5 for all geopolymer mixture and the fly ash to alkali activator ratio was kept at 2.0. The CRGM at 28 days of curing time was exposed to elevated temperature at 200°C, 400°C, 600°C and 800°. The weight loss of the CRGM increases with increasing temperature at all elevated temperatures. However, the density and compressive strength of CRGM decrease with an increase of crumb rubber loading for all elevated temperature exposure. The compressive strength of CRGM reduced due to the fact that rubber decomposes between 200°C and 600°C thereby creating voids. CRGM-15 and CRGM-20 showed cracks developed with rough surface at 800°C. Image obtained from scanning electron microscope (SEM) showed that, the CRGM changed significantly due to the decomposition of crumb rubber and evaporation of the free water at 400°C, 600°C and 800°C. [ABSTRACT FROM AUTHOR]

The aim of this study is the investigation of microstructural effects on cement mortars (CMs) of four different parameters as cement dosage, water/cement ratio, pozzolanic material and curing effect. To achieve the purpose of this study, SEM/EDX, XRD, FTIR and TGA/DTA analysis were performed. A total of 18 mixtures were produced and exposed to water curing (WC) and air curing (AC). In the design of these mixtures, three different cement dosages as 360, 400 and 450 kg/m³ and three different water/cement ratios as 0.40, 0.45 and 0.50 were used. Silica fume (SF) was preferred to observe the effect on microstructural properties clearly of pozzolanic material. In addition, super plasticizer (SP) was utilized in all mixtures and kept constant as 12 kg/m³. The compressive strength, flexural strength and ultrasonic pulse velocity (UPV) of these mixtures were determined at 28 and 90 days. Eight mixtures were chosen to observe the effect of four different parameters in a microstructural sense. XRD, SEM/EDX, FTIR and TGA/DTA analyses were applied to these mixtures. It can be said that microstructural analyses supported the findings obtained from mechanical tests. [ABSTRACT FROM AUTHOR]

This work presents results allowing an unequivocal correlation of the observations of strong nonlinear elastic features of ultrasonic waves (values of the nonlinearity parameters exceeding the thresholds corresponding to undamaged states), with the critical events of the corrosion-induced surface cracking of reinforced cement-mortar specimens. These observations point to the possibility of the early detection of cracking using nonlinear ultrasonic (NLU) techniques. Experimental evidence is presented on the existence of active net mass transport processes, due to wick action, in the course of the corrosion tests, in the experimental conditions of this work. These phenomena might explain the observed abrupt shifting of the nonlinear parameter values (typically increasing and then decreasing post-peak, even reaching values typical of the undamaged state), and, partially, the high variability obtained for the values of the nonlinear parameters in damaged (cracked) states. Finally, some consequences are derived from the point of view of use of the NLU techniques in engineering practice, i.e., in surveys aimed at evaluating reinforced concrete structures affected by corrosion. [ABSTRACT FROM AUTHOR]

The study of geopolymers has become an interesting concern for many scientists, especially in the infrastructure sector, due to having inherently environmentally friendly properties and fewer energy requirements in production processes. Geopolymer attracts many scientists to develop practical synthesis methods, useful in industrial-scale applications as supplementary material for concrete. This study investigates the geopolymerization of fly ash and geothermal silica-based dry activator. The dry activator was synthesized between NaOH and silica geothermal sludge through the calcination process. Then, the geopolymer mortar was produced by mixing the fly ash and dry activator with a 4:1 (wt./wt.) ratio. After mixing homogeneously and forming a paste, the casted paste moved on to the drying process, with temperature variations of 30, 60, and 90 °C and curing times of 1, 3, 5, 7, 14, 21, 28 days. The compressive strength test was carried out at each curing time to determine the geopolymer's strength evolution and simulate the reaction's kinetics. In addition, ATR-FTIR spectroscopy was also used to observe aluminosilicate bonds' formation. The higher the temperature, the higher the compressive strength value, reaching 22.7 MPa at 90 °C. A Third-order model was found to have the highest R2 value of 0.92, with the collision frequency and activation energy values of 1.1171 day−1 and 3.8336 kJ/mol, respectively. The utilization of coal fly ash and silica geothermal sludge as a dry activator is, indeed, an approach to realize the circular economy in electrical power generations. [ABSTRACT FROM AUTHOR]

The separation between repair mortars and the concrete substrate is one of the serious problems in repairing concrete structures. One of the main causes of this separation is the lack of proper curing and, consequently, excessive shrinkage of the repair mortar, which reduces the bond strength between the concrete substrate and the repair layer and has an adverse effect on the compressive and tensile strength of the repair mortars. In this paper, the mechanical properties, shrinkage of repair mortars, as well as their shear and tensile bond strength is investigated on the concrete substrate of different ages under the curings of "abandoned in the laboratory space," "water-submerged" and "curing agent." In-situ "friction-transfer" and "pull-off" methods are used to measure adhesion. Furthermore, the relationships between compressive strength, tensile strength, and readings are obtained from "friction-transfer" and "pull-off" methods on repair mortars and the stress distribution method used in the abovementioned methods are presented using nonlinear finite element analysis (Abaqus/CAE). The results indicate a significant effect of curing method on shrinkage and mechanical properties of repair mortars; as a result, effective curing increases the shear and tensile bond strength at the substrate and repair layer joint boundary. It is also observed that there is a linear relationship between the experimental results obtained from the two methods used in this study with a high correlation coefficient, highly consistent with the results obtained from nonlinear finite element analysis. Thus, they can be used as in-situ methods for determining the compressive and tensile strength of repair mortars. [ABSTRACT FROM AUTHOR]

Over the past 10 years, our research team has holistically studied the environmental aspects of the conservation and restoration of the Hagia Sophia, which is suffering from severe degradation of its wall paintings, including the exfoliation of wall paintings and inner finishing materials, mainly due to salt crystallisation. In the present study, we investigated the influence of environmental factors and wall composition on the hygrothermal behaviour in the structure, such as moisture accumulation and evaporation within the walls, which significantly affect salt crystallisation. The differences in distribution of high moisture content at second cornice are depending on the azimuth, and the high correlation between high moisture content and deterioration severity is significant. A two-dimensional numerical model of the simultaneous transfer of heat and moisture considering the measured material physical properties and wall composition of the exedra wall is developed to quantitatively investigate the influence of environmental factors on moisture accumulation. Numerical results show that infiltrated rainwater tends to accumulate because the original builders used connection mortar, which has a much larger moisture diffusivity than that of modern mortar, and the accumulated water at the bottom of the wall is difficult to drain owing to the shape of the wall. In the northwest exedra, the influence of wind-driven rain on water accumulation is similar to that of runoff rainwater from the upper roofs, which probably causes deterioration over a wide area. In addition, the effect of the deterioration suppression measure by the re-covering of the outer surfaces of the west wall in 2013 is verified, and an appropriate suppression measure against water permeation is examined using a numerical model. [ABSTRACT FROM AUTHOR]

In this study, physical and mechanical properties of light mortars produced with Fly Ash (FA) contributed pumice aggregates, Colemanite (K), Blast Furnace Slag (BFS), Marble powder (MP) were investigated under high temperature. Mortar samples were produced in the dimensions of 40x40x160 mm. At the preparation of mortars, pumice (0-4mm) as a fine aggregate and CEM I 42.5R Portland Cement were replaced with. 1%, 2% and 3% by weight of K respectively and 10%, 20% and 30% of YFC, MT and UK were replaced with cement in light mortars mixture. The produced mortar samples were removed from the mold after 24-hour setting and subjected to a cure at a temperature of 20±2°C in the standard cure pool for 28 days. The flexural and compressive strength of the mortar samples filling the 7th day were determined. Physical properties such as water absorption, porosity and unit volume weight of 28 days cured mortars were determined and flexural and compressive strengths were calculated. At the end of 28th day samples, which were reached its final strength, were exposed to 200 °C, 400 °C, 600 °C and 800 °C heats in High Temperature Oven. It is observed that with increasing temperature, weight loss increases, flexural and compressive strengths decrease in all samples. With the use of mineral additives, it was observed that both the weight losses and the losses in flexural and compressive strengths decreased and the mortars became more resistant to temperature. [ABSTRACT FROM AUTHOR]

This paper studies the possibility of using plastic waste fiber in the mortar, and aims to find the optimum percentage of fiber to improve the properties of mortar. The plastic fiber is used as a volume substitution in dune sand and it used with rates of 5%, 10%, 15%, 20%, 25%, and 30%. Specifically, the mechanical properties as compressive and tensile strength and durability performance as capillary and immersion absorption, the depth of chloride penetration and the loss of weight were measured. The results show that the incorporation of waste plastic fiber reduces the compressive strength and enhances the flexural tensile strength. The use of waste plastic fibers indicates the good behavior to mortars in aggressive environment. [ABSTRACT FROM AUTHOR]

This work is an extensive experimental study on the corrosion behavior of reinforced cementitious mortars containing industrial byproducts and waste materials. In particular, calcareous (C-class) fly ashes, iron mill scale and Electrolytic Manganese Dioxide (E.M.D.) waste were used as additives in mortars production. The abovementioned materials were used without any prior treatment or management and replaced the cement in concrete mixing by 10% wt. of cement weight. For the experimental set-up, reinforced mortars were prepared and exposed to coastal area for 12 months, while some of them were remained in a salt spray cabin for 60 days. The corrosion monitoring was performed by electrochemical and mass loss measurements, while chloride content, porosity, carbonation and mineralogy of mortars were also estimated. The results indicate, that there is a development in durability and chloride penetration resistance of composites comparing with the conventional mortars at late ages. At the same time, it was also observed that their chemical composition and fineness, control the diffusion of CO2 into the pore system and lead to increased carbonation of composite mortars. The challenge of this work is the production of eco-friendly composites with high chloride and carbon dioxide penetration resistance. [ABSTRACT FROM AUTHOR]

This paper aims to study strength properties, UPV, and weight changes exposed to sulfate attack, and microstructural properties of geopolymer mortar prepared using metakaolin and red-mud as binder materials by mixing with river sand replaced partially by limestone, marble and basalt powder with different ratios (25%, 50%, and 75%) as filler materials, the mix proposed were activated by sodium silicate and sodium hydroxide solutions (12mol). The proposed samples were exposed to 10% of magnesium and sodium sulfate solutions for various periods of 60, 120, and 180 days to investigate the durability properties of the manufactured geopolymer mortar. The experimentally obtained results uncover that the prepared geopolymer mortar’s strength properties increase at 60 days for all the proposed mixes, while at 180 days; the geopolymer mortar suffers a significant loss. Change in weight increase obviously between 10.83% and 13.65% for 60 days and decrease gradually for 120 days between 9.22% and 10.19% to reach a stable value between 120 and 180 days. Furthermore, to evaluate this work, the Scanning Electron Microscopy and X-ray Diffraction methods were investigated. [ABSTRACT FROM AUTHOR]

To reduce the energy use of the European building stock, a large potential can be found in the renovation of cultural heritage buildings. However, insulating these valuable masonry facades often increases the risk of moisture-related damage phenomena such as mold growth and frost damage. Therefore, detailed heat, air and moisture simulations are required to quantify and assess these risks. One of the unknown parameters in the simulations for historic masonries is the hygric interface resistance between the bricks and the lime mortars. Consequently, microfocus X-ray scans are performed during a capillary water absorption test on brick–lime mortar–brick samples to increase the insight into the moisture transport over the interface, dependent on the capillary pressure at the interface and the curing conditions of the mortar. The hygric interface resistance is found to be highly dependent on both capillary pressure and the curing conditions of the mortar. For the exact quantification of the interface resistance, highly detailed moisture transport and moisture storage properties of the brick and mortar are a prerequisite. [ABSTRACT FROM AUTHOR]

• Terme di Baia is one of the most important archaeological sites in Southern Italy. • Microstructural and compositional examination of coating mortars. • Long-lasting use of a valuable mix design created with local raw materials. • Secondary phases improved the technological properties of mortars. Ancient pozzolanic mortars show the high technological quality achieved by Roman construction workers, due to their ' excellent state ' of preservation in every environment. These workers well knew that thanks to the combination of lime with specific volcanic products (pozzolana), mortar and concrete become hydraulic, allowing underwater hardening and increasing mechanical strength. The use of pozzolana in a mortar provides the underwater curing (hydraulic limes) of whatever construction with higher speed compared to carbonation processes of slaked lime. Whenever pozzolana is not available, it is substituted by ceramic fragments, which possess similar hydraulic properties. This research focuses, for the first time, on the detailed characterization of mortars coming from the Thermal Complex of Baia, which represents one of the most important archaeological sites in the Campania region. Thanks to several thermal springs, the ancient city of Baiae (Campi Flegrei) was the holiday resort of the Roman aristocracy. The former Soprintendenza Archeologia della Campania , allowed us to perform non-invasive, but representative, sampling of mortars that were characterised by multianalytical methodologies (POM, XRPD, SEM-EDS, TGA, and MIP) providing useful information on possible future activities of restoration. Results confirmed the expertise of Roman workers, who skilfully combined volcanic tuff aggregate, hydrated lime, and ceramic fragments. In particular, the typical zeolitic mineral association of phillipsite > chabazite > analcime found in the tuff aggregate pointed out their provenance from the Neapolitan Yellow Tuff related to the volcanic activity of Campi Flegrei of ca. 15 ka BP. The most relevant characteristic detected in all studied samples is the mortar hydraulicity testified by evidences such as reaction rims between pozzolana and binder, Hydraulicity Index (HI), and thermal analyses investigation. Also, composition of secondary mineralogical phases in the cementiceous matrix is particularly relevant. Distinctive is the contemporary presence of C-A-S-H gel, calcite and gypsum. C-A-S-H gel is derived from lime/ceramic fragments reaction; calcite is likely related to the partial reaction of underburned lime; and gypsum could be ascribable to the sulphation process of calcite. These secondary minerogenetic products fill pore space and enhance bonding in pumice fragments, thus contributing to long-term durability of mortars. [ABSTRACT FROM AUTHOR]

This paper investigates the cement hydration, and the slag reaction contributes to the compressive strengths of mortars mixed with ground river sand (GRS) and ground-granulated blast furnace (GGBF) slag with different particle sizes. GRS (inert material) and GGBF slag (reactive material) were ground separately until the median particle sizes of 32 ± 1, 18 ± 1, and 5 ± 1 micron and used to replace Portland cement (PC) in large amount (40–60%) by weight of the binder. The results showed that, at the early age, the compressive strength obtained from the cement hydration was higher than that obtained from the slag reaction. The results of compressive strength also indicated that the GGBF slag content and particle size play important roles in the slag reaction at the later ages, whereas cement hydration is more prominent at the early ages. Although the results could be expected from the use of GGBF slag to replace PC in mortar or concrete, this study had presented the values of the compressive strength along with ages and the finenesses of GGBF slag that contributed from cement hydration and from GGBF slag reaction. [ABSTRACT FROM AUTHOR]

Cracking tendency is one of the important performances of dry-mixed plastering mortar (DMPM). Environmental condition is a key factor to affect the cracking tendency of DMPM. For the purpose of evaluating the cracking resistance of DMPM and revealing the influence of environmental conditions on the cracking tendency of DMPM, a series of experiments were performed on restriction-induced cracking behaviors as well as free shrinkage, water loss, and mechanical properties of DMPM. The restricted shrinkage tests were based on ring tests and plate experiments. The results showed that the initial drying age exhibits significant influence on the cracking tendency of DMPM, and there was a stress balance period when the initial drying age was 2 days. But, the phenomena cannot be observed when the initial age was 3 d, 5 d, and 7 d. In order to eliminate the cracking tendency of DMPM, it should avoid water loss from the plaster layer during construction in practical engineering, especially, before initial drying ages. [ABSTRACT FROM AUTHOR]

The Cluny Priory of Castelletto Cervo (Biella, Piedmont) was deeply investigated from 2006 to 2014, in a multidisciplinary project. This contribution deals with the methodological approach followed for the archaeometric study of mortars, and the results in term of material knowledge and reading of the building phases in a time interval of about a millennium. Petrographic observations combined with microchemical data showed that the local raw materials were exploited during a very long time span: the aggregates are polygenic sands, with a high percentage of volcanic rock grains, coming from the hydric basins of the Cervo River, and its tributary Ostola; the binders are mainly Mg-bearing lime, with a strong hydraulic component due to the reaction between the binder and the volcanic grains of the aggregate. A good match between mortars composition and building phases was determined only for some of the earliest phases of the monastery. [ABSTRACT FROM AUTHOR]

Since 1960s, mortars have been exploited as a potential material for radiocarbon dating and, despite the fact that this methodology appears very simple in its principles, some measured radiocarbon ages were definitely different from the expected historic ages. The paper concerns to the characterisation of mortars from three Andalusian castles (Spain) by means of different mineralogical techniques in order to control “contamination effect” that could affect age estimation. Several mixtures of binders and aggregates composed the archaeological mortars; lime-based or gypsum-based binders were distinguished whereas the aggregates varied from carbonates to intrusive igneous rocks. The radiocarbon dating provided good results for lime-based mortars with silicate aggregate; conversely, for other specimens the method for sample preparation (Cryo2SoniC) was improved increasing the ultrasonic time and decreasing the mesh size. The research points out the importance of a multi-analytical approach aimed at improving a widely accepted protocol for 14 C dating of archaeological mortars. [ABSTRACT FROM AUTHOR]

Mortar is of all masonry components the most difficult to be experimentally characterized in heritage buildings. This article investigates the possibility of combining different in-situ and laboratory minor destructive testing (MDT) techniques to assess the strength of mortar in historical brickwork. Lime mortar and clay brick walls were built in the laboratory and then tested in order to derive empirical correlation rules among three different MDT techniques: double punch test (DPT), helix pull-out test (HPT), and pin penetration test (PPT). The outcomes of this activity were used eventually to assess the mortar properties of an important historical heritage structure, Casa Puig i Cadafalch, located near Barcelona. The research is intended to promote the use of MDT in studies and conservation works on built cultural heritage by providing criteria for the evaluation of the strength of existing mortar with respectful sampling and testing techniques. [ABSTRACT FROM AUTHOR]

As the natural resources needed for the construction sector arelimited, new practices are being adopted for the managementof waste generated nowadays, including the use of constructionand demolition waste as aggregates for concrete and mortar.Considering the different typologies in construction wastes,ceramics are the second most representative material; thereforeit is important to validate their feasibility as a total orpartial replacement of natural aggregates. This work presentsa study of the properties in fresh state (consistency, density andair content) of mortars containing aggregates obtained fromrecycled ceramics, and their influence on the subsequent propertiesin the hardened state. A statistical analysis of experimentaldata was carried out by establishing regression coefficients,and then a triple-entry graph was obtained, allowing the differentproperties of mortars to be easily linked and simplifyingthe prediction of the relationships they will present since themixture design phase. [ABSTRACT FROM AUTHOR]

In this paper, the mechanical properties of concrete with an added residue of the petrochemical industry (at levels of 10, 20, 30%), called catalytic cracking catalyst residue (FCC), are evaluated. The mechanical properties evaluated include compressive strength, modulus of elasticity, flexural strength, and ultrasonic pulse velocity. Two reference materials, portland cement concrete without addition and added with 20% of metakaolin (MK), were used. These tests were performed up to 360 days of curing age. Based on the results obtained, correlations were established between the different properties evaluated. The best mechanical performance was obtained with 10% FCC as a cement replacement. [ABSTRACT FROM AUTHOR]

The development of a numerical procedure for the finite element analysis of anchors dynamically penetrating into saturated soils is outlined, highlighting its unique features and capabilities. The mechanical behaviour of saturated porous media is predicted using mixture theory. An algorithm is developed for frictional contact in terms of effective normal stress. The contact formulation is based on a mortar segment-to-segment scheme, which considers the interpolation functions of the contact elements to be of order N, thus overcoming a numerical deficiency of the so-called node-to-segment (NTS) contact algorithm. The nonlinear behaviour of the solid constituent is captured by the Modified Cam Clay soil model. The soil constitutive model is also adapted so as to incorporate the dependence of clay strength on strain rate. An appropriate energy-absorbing boundary is used to eliminate possible wave reflections from the artificial mesh boundaries. To illustrate the use of the proposed computational scheme, simulations of dynamically penetrating anchors are conducted. Results are presented and discussed for the installation phase followed by ‘setup’, i.e., pore pressure dissipation and soil consolidation. The results, in particular, reveal the effects of strain rate on the generation of excess pore pressure, bearing resistance and frictional forces. The setup analyses also illustrate the pattern in which pore pressures are dissipated within the soil domain after installation. Hole closure behind a dynamic projectile is also illustrated by an example. [ABSTRACT FROM AUTHOR]

The Pino del Oro gold mines, located in the northwestern Iberian Peninsula and more specifically in the Spanish province of Zamora, form part of the country?s Roman Age mining heritage. These mines differ from all the others in the empire in one respect: they are characterised by the presence of quern-like depressions found in the nearby granitic outcrops where miners ground the ore. A series of petrological techniques was used to determine the most appropriate procedure for gathering information that would help clarify the significance of these man-made formations and whether the type of granite was a conditioning factor in the choice of grinding site. An analysis of the results yielded by the techniques deployed to characterise the two types of granite where the bedrock mortars are found showed that ultrasound velocity (Vp) and the hardness index are the two most suitable for futher research. On the grounds of the Vp and hardness fingings, a hypothesis is put forward on how to determine the stage of usability of the bedrock mortars. [ABSTRACT FROM AUTHOR]

The article presents the problems encountered while completing the tasks related to the technical preparation of mortars. The first part describes the binding rules applied to determine the zero settings of the sight and the zero line of sight, and to check and define adjustments for the line of sight deviation. The paper presents a practical solution making it possible to verify quickly whether the determined zero settings are correct. The next part focuses on significant problems related to the determination of individual adjustments in subunits equipped with mortars. The final part contains a summary, conclusions drawn from the analysis and experience gained in practice during firing, and also the proposal of relevant solutions. [ABSTRACT FROM AUTHOR]

The Provisional Irish Republican Army (PIRA) repeatedly showed itself to be one of the most inventive and adaptive of all the violent non-state actors who operated in the latter part of the twentieth century. Among its most innovative exploits was the PIRA's successful development and fielding -- spanning almost its entire operational lifetime -- of improvised mortar systems. This chapter will trace the sustained development of mortars, including the underlying motivations for pursuing mortars as a complex engineering effort, the process by which the development took place and the underpinnings of its success. The discussion will show that the PIRA's mortar development program was born out of tactical necessity but enabled by good organizational practices and the organization's access to materials, expertise and places in which to leverage these. [ABSTRACT FROM AUTHOR]

Guidance with traditional trajectory correction scheme usually starts from the trajectory apex time to reduce drag penalties early in flight; however, this method cannot get the max trajectory correction capability of canards according to our analysis. This paper presents an optimized trajectory correction scheme by taking different control phases of canards in ballistic ascending segment and ballistic descending segment. Simulation indicates that the optimized trajectory correction can improve the trajectory correction capability greatly. The result of an example trajectory and Monte Carlo simulations with the predictive guidance law and the trajectory tracking guidance law testifies the effectiveness of the optimized trajectory correction scheme. [ABSTRACT FROM AUTHOR]