Papers by Keyword: Mortar

Abstract: Sugarcane bagasse ash (SCBA) is a by-product of the ethanol and sugar industry. SCBA is generally used as fertilizer or dumped in landfill, which has led to increasing environmental problems. In the recent years, SCBA has been investigated in the field of construction materials due to its pozzolanic character. This research aims at examining some physical and mechanical properties of mortars with partial replacement of sugarcane bagasse ash from sugar cane refineries. In the present case, the cement substitution was made with SCBA at 0%, 15%, and 30% of the binder (Cement + ash). The physical and mechanical testing of the mortar was carried out to determine the effect of ash addition on porosity, density, flexural and compressive strengths of the mortar. In general, the findings revealed that the mechanical and physical behavior of the mortar mixtures improved over time because of pozzolanic effects. On one hand, the physical changes were relatively restricted and do not show a well-established trend. On the other hand, reduction of mechanical strength was observed with the addition of SCBA, and with a 15% cement replacement percentage, it is possible to obtain a material with favorable physical and mechanical properties.

Abstract: Hydrothermal carbonization (HTC) involves a thermochemical process at high temperature to reduce lignin and extractive in organic material using water as a medium. HTC produces a solid product known as hydrochar. Utilization of coconut coir in the concrete or mortar is an alternative to reducing agriculture waste. The application of natural fibers as aditif material in concrete and mortar effect the characteristics of cement mortar. The aim of this study is to investigate the impact of introducing coconut coir on mechanical properties of cement mortar at 28 days. This research used coconut coir, with a diameter of 0.420-0.149 mm. First, the coconut coir was boiled in a 5% potassium hydroxide (KOH) solution at 80°C for 30 minutes. Then followed the hydrothermal carbonization process for 1, 2, and 3 hours at 160°C. This research used a sand-to-cement ratio of 1:2.75 (by weight) and a water-to-cement ratio of 0.46. The hydrochar used in this study was 1% of cement (by weight). In the context of this research, physical and mechanical properties were observed such as flowability, compressive strength, flexural strength, and water absorption. The duration of the hydrothermal carbonization affected flowability, compressive strength and water absorption. It enhanced flowability, compressive strength, and water absorption. On the other hand, the hydrothermal carbonization duration increased as the flexural strength decreased.

Abstract: Slurry Infiltrated Fiber CONcrete (SIFCON) is a particular type of fiber-reinforced concrete with a high fiber content that shows high strength, with a significant improvement in properties such as durability, ductility, and toughness, which has greater energy absorption capacity along with good mechanical properties. In the last decade, much research has been conducted on SIFCON, mainly focused on changing the ratio, shape, or type of fibers to improve some mechanical properties and replacing some components of mortar of SIFCON to enhance its durability. In this paper, an attempt has been made to review the research results in improving the properties of SIFCON by using different types and quantities of fibers, as well as knowing the extent to which this type of concrete is affected by using alternative materials for mortar components. The review provides essential information about SIFCON that researchers in this field may encounter.

Abstract: Direct reuse of precast concrete elements is possible if disassembly is considered in the design phase. An unusual way of designing for disassembly is to use “wet” joints as usual but to optimise the mortar to be less strong and, therefore, easier to remove at the end of the life of the building. A method is presented to test mortars with lime content to determine the shear capacity in the connection between mortar and concrete. Tests are performed with and without an applied normal force and with and without steel bars through the interface. The results show that applying a lime content to the mortar reduces the compressive strength, shear strength and flexural strength. Using steel bars in the connections increases the ductility from less than 1 mm to several mm at the point of failure. The results can be used in future checks of mortar joints in buildings, where it is required to have a minimum strength during the service life and a maximum strength when dismantling. The future mortar requirements will depend on the disassembly method.

Abstract: Different sand quarries used to build construction in Morelia, México were analyzed, the optimum mortar configuration was obtained based in the analysis of sand aggregates. Different mixes mortar configuration with Portland cement, masonry mortar, lime, sand, and water, were elaborated and characterized. Two different configurations were proposed, one with the addition of 1/4 of lime and the second with 1/2 of mortar masonry in relation to cement ratio. 3 different quarries were studied, and the proportion of sand were from 2.25 to 4. All the samples were analyzed by flowability and wet electrical characterization. The flowability of all different mix configuration pastes was studied to comprehend the sand-water relation of the mortar mix and to observe the different water requirements in function of the sands proportion and quarry origin. The results shows that the sand proportion 2.25 and 3.25 in configuration 1 (1/4 lime) had 123 and 124 % respectively, the highest values. The flowability of sand proportion in configuration 2 (1/2 masonry mortar) were closed and above 100%. The mortar samples were also characterized by the electric resistivity test to analyze the porosity of the mortar in relation to the sand aggregate. All the sand proportion of configuration 1 were under the minimum limit, the 2.5 sand proportion were the closest with 9.51 kΩ-cm. With the configuration 2, 3.5 sand proportion at 7 days from bank J show the highest value 15.48 kΩ-cm.

Abstract: The normal and tangential adhesive strength between bricks and mortar in bed joints is the main parameter that determines the performance of masonry under biaxial stress conditions. This research aims to determine the possibility of increasing the tangential adhesive strength (shear) of masonry by using mortars reinforced with PET fibres obtained from recycled plastic bottles. Shear tests are proposed on simplified brick masonry specimens made with mortars containing PET fibres in percentages of 0.5%, 1% and 1.5% of the mass of cement and sand. It has been determined that the addition of PET fibres in percentages no greater than 1% increases the tangential bond strength. The addition of 0.5% PET fibres increases the tangential adhesive strength by 37% and 1% PET by 60%, while the addition of 1.5% PET fibres decreases the studied strength by 22.86%.

Abstract: This paper studies the effect of both perlite and pozzolan powders as cement substituents. First, it addresses the mechanical properties of pozzolanic mortar in the short term, i.e., with a schedule of 7, 14 and 28 days. Next, in order to extend the analysis related to the porosity of the designed mortars, the water absorption is studied. The provided results indicated that the compressive strengths of the pozzolanic mortars were lower than those of the reference mortar. However, among the tested pozzolanic mortars, those containing 10% of perlite displayed superior strengths. Additionally, while the water absorption values for pozzolanic mortars were higher than those of the reference mortar, the inclusion of 10% of perlite in the mortar resulted in lower water absorption compared to the other pozzolanic mortars.

Abstract: 3D concrete printing is an innovative construction process based on fully autonomous material deposition. One of the challenges of implementing this technology is the development of printable concrete formulations, as this material must exhibit particular fresh-state properties. Among these, buildability is one of the most important. This property describes the material's ability to support weight at very early ages, allowing a layer-by-layer construction. Therefore, this paper aims to evaluate two approaches for improving concrete buildability: the optimization of the superplasticizer dosage and the external application of quick-setting admixture. The results showed that reducing superplasticizer content improved buildability by increasing the static yield strength. However, this approach has a collateral disadvantage as concretes presented problems during extrusion. On the other hand, the results of cylinder stability and Vicat tests indicate that the external application of quick-setting admixture leads to concretes with improved buildability without affecting the initial workability and a faster hardening process. According to these results, the latter approach can potentially be applied in small and large-scale 3D printing.

Abstract: The use of industrial waste materials as a substitute for cement in the manufacture of mortar is an alternative approach to reduce carbon dioxide emissions in building construction. In this study, processed waste tea ash (PWTA) obtained from the extraction tea plant was used to partially replace 0-40% cement in the manufacture of mortar. The effects of PWTA on the basic engineering properties of mortar are evaluated and compared to mortar without PWTA. Test results showed that workability and density of mortar decreased with increases in the PWTA content. Furthermore, no decline in compressive strength of concrete was observed up to 20% replacement of cement with PWTA at 7, 28 and 90 days and beyond that, the compressive strength decreased. Results obtained from this study indicate that PWTA can be used as partial replacement of cement up to 20% with comparable strength with normal mortar. This approach helps to minimize the usage of cement in mortar production and can reduce the negative impact of PWTA on the environment.

Abstract: Waste materials are deemed an environmental burden; although, they can be recycled in the production of sustainable building materials. The aim of this study is to develop an aesthetic architectural rendering green mortar with utilizing recycled waste colored glass as supplementary fine aggregate. Limestone Calcined Clay Cement (LC3) has been prepared as a green and sustainable binder by replacing 60 wt% of white Portland cement () with a blend of limestone (LS) powder and metakaolin (MK) with a LS: MK of 1:2 (wt%). LC3-based mortars were prepared in which the binder was combined with expanded polystyrene beads (EPS) as fine aggregate with aggregate volume content of 75%. EPS was partially replaced with recycled waste glass (RWG) at various percentages of 10, 20, and 30 vol.%. Bulk density, thermal conductivity, solar reflectivity and flexural strength of the hardened mortars were determined after 7days of curing. The contribution of the newly developed mortars into reducing internal thermal loads and energy use has been evaluated for administrative/ office building in EGYPT. The mortars incorporating 10 and 20vol.% of RWG possessed thermal conductivity values in the range of thermal insulation rendering mortars. The incorporation of RWG led to enhanced solar reflectivity, an increase by about 77% has been achieved relative to the traditional one coat - rendering mortar; in addition, the newly developed rendering mortar provided a reduction in electric cooling energy annual consumption by about 30%