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The main aim of the current study is to investigate the effect of Anti-Crack HP 67/36 glass fibre on the mechanical performance of mortars made of cement, with a focus on post-cracking evaluations using the digital image correlation (DIC) technique.

Experimental tests were carried out on 36-mm long fibres at 0.8% by volume and added to the normal strength (NSM), high strength (HSM) and high strength mortar with fly ash (HSMFA) mortars. CEM I 52.5 CP2 NF, CEM II/A-L 42.5 NF and CEM III/C 32.5 N-SR PM were used for each series of mortar to assess the performance of the glass fibres with the types of cement. F-class fly (FA) ash was used to reduce global CO₂ emissions.

The mortar’s strength decreased as the cement types changed from CEM I to CEM II and III. However, due to changes in the portlandite content of the cement, water porosity increased for both types of mortar, without and with fibre. It was also found that using glass fibre increased flexural strength more than compressive strength, regardless of the type of cement used. For all the strength classes, it was found that the mortar mixes with CEM I had the highest critical crack opening (w_c) and fracture energy (G_F), followed by CEM II and III. No significant effects were observed in the mortar’s property by replacing fly ash (12%).

Only mortars were formulated in this study, but the results must be verified at the concrete scale.

Validation of the DIC technique to characterize the post-cracking behaviour of cement-based material. Use of glass fibres to improve the material’s resistance to cracking.

Use of CEM II and CEM III cements with low CO₂ footprint instead of CEMI without altering the mechanical performance of the material.

The work is a further contribution to studying the cracking behaviour of several series of variable mortars depending on the resistance class and the type of cement used.

The purpose of this study is to investigate the effect on flexural strength of fire-damaged concrete repaired with high-strength mortar (HSM).

Reinforced concrete beams with dimension of 100 mm × 100 mm × 500 mm were used in this study. Beams were then heated to 400°C and overlaid with either HSM or high-strength fiber reinforced mortar (HSFM) to measure the effectiveness of repair material. Repaired beams of different material were then tested for flexural strength. Another group of beams was also repaired and tested by the same procedure but was heated at higher temperature of 600°C.

Repair of 400°C fire-damaged samples using HSM regained 72 per cent of its original flexural strength, 100.8 per cent of its original toughness and 56.9 per cent of its original elastic stiffness. Repair of 400°C fire-damaged samples using HSFM regained 113.5 per cent of its original flexural strength, 113 per cent of its original toughness and 85.1 per cent of its original elastic stiffness. Repair of 600°C fire-damaged samples using HSM regained 18.7 per cent of its original flexural strength, 25.9 per cent of its original peak load capacity, 26.1 per cent of its original toughness and 22 per cent of its original elastic stiffness. Repair of 600°C fire-damaged samples using HSFM regained 68.4 per cent of its original flexural strength, 96.5 per cent of its original peak load capacity, 71.2 per cent of its original toughness and 52.2 per cent of its original elastic stiffness.

This research is limited to the size of the furnace. The beam specimen is limited to 500 mm of length and overall dimensions. This dimension is not practical in actual structure, hence it may cause exaggeration of deteriorating effect of heating on reinforced concrete beam.

This study may promote more investigation of using HSM as repair material for fire-damaged concrete. This will lead to real-world application and practical solution for fire-damaged structure.

The aim of this research in using HSM mostly due to the material’s high workability which will ease its application and promote quality in repair of damaged structure.

There is a dearth of research on using HSM as repair material for fire-damaged concrete. Some research has been carried out using mortar but at lower strength compared to this research.

The purpose of this paper is to develop an alternative new ternary geopolymer mortar (MKSP) to resolve a traditional mortar problem which exhibits several disadvantages, including poor strengths and surface microcracks and the CO₂ air pollution.

The MKSP ternary binder was produced using metakaolin (MK), slag (S), and palm oil fuel ash (POFA) activated with an alkaline mixture of sodium silicate (Na₂SiO₃) and 10 M NaOH in a mass ratio of 2.5. Seven different mix proportions of MK, slag, and POFA were used to fabricate MKSP mortars. The water-to-binder ratio was varied between 0.4 and 0.5. The mortars were heat cured for 2 h at 80°C and then aged in air. Flexural stress and strain, mortars flow and compressive strength were tested. Furthermore, the mortars were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) analyses.

The results showed that the sample MKSP6, which contained 40 percent MK, 40 percent slag, and 20 percent POFA, exhibited high compressive strength (52 MPa) without any cracks and flexural strength (6.9 MPa) at 28 days after being cured for 2 h at 80°C; however, the MKSP7 mortar with optimal strength of 55 MPa showed some surface cracks . Further, the results of the XRD, SEM, and FTIR analyses indicated that the MKSP mortars primarily consisted of a crystalline (Si+Al) phase (70 percent) and a smaller amorphous (Si+Ca) phase (30 percent).

The MKSP ternary geopolymer mix has three limitations as an importance of heat curing for development early strength, POFA content less than 20 percent to gain high normal strength and delaying the sitting time by controlling the slag content or the alkali activator type.

The use of geopolymer materials binder in a real building is limited and it still under research, Thus, the first model of real applied geopolymer cement in 2008 was the E-Crete model that formed by Zeobond company Australia to take the technology of geopolymer concrete to reality. Zeobond Pty Ltd was founded by Professor Jannie S.J. van (van Deventer et al., 2013), it was used to product precast concrete for the building structure. The second model was PYRAMENT model in 2002 by American cement manufacturer Lone Star Industries which was produced from the development carried out on inorganic alumino-silicate polymers called geopolymer (Palomo et al., 1999). In 2013 the third model was Queensland’s University GCI building with three suspended floors made from structural geopolymer concrete containing slag/fly ash-based geopolymer (Pathak, 2016). In Australia, 2014, the newly completed Brisbane West Wellcamp airport becomes the greenest airport in the world. Cement-free geopolymer concrete was used to save more than 6,600 tons of carbon emissions in the construction of the airport. Therefore, the next century will see cement companies developing alternative binders that are more environmentally friendly from a sustainable development point of view.

Production of new geopolymer binder of mortar as alternative to traditional cement binder with high early and normal strength from low cost waste materials, less potential of cracking, less energy consumption need and low carbon dioxide emission.

In recent years, fire accidents in engineering structures have often been reported worldwide, leading to a severe risk to life and property safety. The present study is carried out to evaluate the performance of Ground Granulated Blast Furnace Slag (GGBS) and fly ash–blended laterized mortars at elevated temperatures.

This test program includes the replacement of natural river sand with lateritic fine aggregates (lateritic FA) in terms of 0, 50 and 100%. Also, the ordinary Portland cement (OPC) was replaced with fly ash and GGBS in terms of 10, 20, 30% and 20, 40 and 60%, respectively, for producing blended mortars.

This paper presents results related to the determination of residual compressive strengths of lateritic fine aggregates-based cement mortars with part replacement of cement by fly ash and GGBS exposed to elevated temperatures. The effect of elevated temperatures on the physical and mechanical properties was evaluated with the help of microstructure studies and the quantification of hydration products.

A sustainable cement mortar was produced by replacing natural river sand with lateritic fine aggregates. The thermal strength deterioration features were assessed by exposing the control specimens and lateritic fine aggregates-based cement mortars to elevated temperatures. Changes in the mechanical properties were evaluated through a quantitative microstructure study using scanning electron microscopy (SEM) images. The phase change of hydration products after exposure to elevated temperatures was qualitatively analyzed by greyscale thresholding of SEM images using Image J software.

A study on the mechanical characteristics of cementitious mortar reinforced with basalt fibres at ambient and elevated temperatures was carried out. To investigate their effect, chopped basalt fibres with varying percentages were added to the cement mortar.

All the specimens were heated using a muffle furnace. Flexural strength and Compressive strength tests were performed, while monitoring the moisture loss to evaluate the performance of basalt fibre reinforced cementitious mortars at elevated temperatures.

From the study, it is clear that basalt fibres can be used to reinforce mortar as the fibres remain unaffected up to 500 °C. Minimal increases in flexural strengths and compressive strengths were measured with the addition of basalt fibres at both ambient and elevated temperatures. SEM pictures revealed fibre matrix interaction/degradation at different temperatures.

The current study shows the potential of basalt fibre addition in mortar as a reinforcement mechanism at elevated temperatures and provides experimental quantifiable mechanical performances of different fibre percentage addition.

Durability, high-temperature resistance, impact and blast resilience, radiation-shielding properties, irradiation endurance and - of course - good mechanical properties are required of the cementitious composites to be used in a variety of high-performance structures. Among these, tall buildings, road and railway tunnels, off-shore platforms, gasification plants, wind and solar mills for the production of "clean" energy should be mentioned, as well as nuclear power plants, and radioactive- and hazardous-waste repositories. Hence, understanding, measuring and modelling concrete behavior under extreme environmental conditions is instrumental in making concrete structures safer and more efficient. To this end, the hot and residual properties associated with the exposure to high temperature, fire and thermal shock are treated in this paper. Reference is made to ordinary vibrated concrete (Normal-Strength Concrete - NSC), as well as to a number of innovative cementitious composites, such as Fiber-Reinforced Concrete - FRC, High-Performance/High-Strength Concrete - HPC/HSC, Ultra High-Performance/Very High-Strength Concrete - UHPC /VHSC, Self-Compacting/Consolidating Concrete - SCC, Light-Weight Concrete - LWC, shotcrete and high-strength mortars. It is shown that these materials can be "tailored" according to a variety of requirements and functions, even if several aspects of their behavior (like spalling in fire and long-term mechanical properties under sustained high temperature) are still open to investigation.

This paper aims to analyse the behaviour of dune sand mortars with the addition of ceramic waste. The objective of improving the performance of these modified mortars was evaluated in terms of accelerated carbonation performance.

The effect of these recycled materials was studied in an experimental programme through several tests. The carbonation depth was determined using a classical phenolphthalein test. The mass fractions of Ca(OH)₂ and CaCO₃ were calculated using thermogravimetric analysis, water absorption occurring through capillary action and open porosity, and the mechanical characteristics were measured after subjecting the materials to wetting–drying cycles.

The results show that using ceramic waste provides better performance in terms of water absorption by capillary action, open porosity and carbonation penetration.

This research is a study of the incorporation of ceramic waste up to 10 per cent in dune sand mortar. The choice of using ceramic waste to produce dune sand mortars has benefits from economic, environmental and technical points of view and offers a possibility for improving the durability of mortars.

This paper aims to describe carbon fiber reinforced plastics (CFRP) bars as a way to strengthen a 40-year-old stone arch bridge. To investigate effectiveness of the strengthening method, fielding-load tests were carried out before and after strengthening.

High-strength CFRP bars with minor radius, high tensile strain and good corrosion resistance were used in this reinforcement. The construction process for strengthening with CFRP bars – including CFRP bars cutting, crack grouting, original structural surface treatment, implant drilling, CFRP bars installation and pouring mortar – was described. Ultimate bearing capacity of the bridge after strengthening was discussed.

The results of concrete stress and deflection show that the strength and stiffness of the strengthened bridge are improved. The strengthened way with CFRP bars is feasible and effective.

This paper describes CFRP bars as a way to strengthen a 40-year-old stone arch bridge.

This study aims to investigate the properties of mortar made from a bottom ash substitute as a sustainable construction material. It is believed that the use of cement in concrete construction contributes to the release of carbon dioxide into the atmosphere, which has been a consistent increase in recent years. The utilization of bottom ash waste is expected to reduce pollution associated with cement production.

Bottom ash is used as replacement materials for cement and fine aggregate in the manufacture of mortar. Bottom ash substituted for cement of 10%, 20% and 30% of the total weight of the binder, whereas bottom ash substituted for the fine aggregate of 30%, 40% and 50% of the total weight of the sand. Binder properties were determined using scanning electron microscopy and energy dispersive X-ray. Meanwhile, the fresh properties (slump flow) and hardened properties were determined (compressive strength and mass density). In the hardened properties test, two types of curing were used: water and sealed curing.

The compressive strength of mortar decreased as the amount of bottom ash as cement replacement. However, the compressive strength increased when bottom ash was used as aggregate replacement. Additionally, bottom ash was sufficient as a substitute for fine aggregate than as a substitute for cement.

This research presents test results that are more straightforward to apply in the construction site.

To contribute for a reliable estimation of the compressive strength of unreinforced masonry from the properties of the constituents (units and mortar).

Sophisticated non‐linear continuum models, based on damage, plasticity, cracking or other formulation, are today standard in several finite element programs. The adequacy of such models to provide reliable estimates of masonry compressive strength, from the properties of the constituents, remains unresolved. The authors have shown recently that continuum models might significantly overestimate the prediction of the compressive strength. Hence, an alternative phenomenological approach developed in a discrete framework is proposed, based on attributing to masonry components a fictitious micro‐structure composed of linear elastic particles separated by non‐linear interface elements. The model is discussed in detail and a comparison with experimental results and numerical results using a standard continuum model is provided.

Clear advantages in terms of compressive strength and peak strain prediction were found using the particle model when compared with standard continuum models. Moreover, compressive and tensile strength values provided by the model were found to be particle size‐ and particle distortion‐independent for practical purposes. It is also noted that size‐dependent responses were obtained and that shear parameters rather than tensile parameters were found to play a major role at the meso‐level of the phenomenological model.

This paper provides further insight into the compressive behaviour of quasi‐brittle materials, with an emphasis on the strength prediction of masonry composites. Reliable prediction of masonry strength is of great use in the civil engineering field, allowing one to reduce experimental testing in expensive wallets and to avoid the usage of conservative empirical formulae.