Sand Mortar Research Articles

The influence of fine recycled asphalt pavement aggregates on the properties of self-compacting mortar in fresh and hardened state

Sustainable development is a contemporary concern in the field of asphalt pavements, as road construction consumes a significant amount of new aggregates. Furthermore, road maintenance necessitates the milling of old pavement layers, which generates a substantial quantity of bituminous material waste. This study explores the use of recycled sand from asphalt waste as a substitute for 0, 25, 50, 75, and 100% of natural sand in self-compacting mortar, aiming to achieve both sustainable and economical asphalt production. The differences in physical properties between natural sand (NS) and fine recycled asphalt pavement (FRAP) aggregates are analyzed and compared. The characteristics of the various self-compacting mortars are measured, including spread, flow time, as well as compressive and tensile strength, shrinkage and sorptivity. Compared to the control mortar, the mortars containing RPAS exhibit a rougher surface, additional pores, and more complex pore structures. The need for superplasticizers increases with the substitution rate, as do the rheological parameters. The results indicate that recycled mortar can be an alternative to natural sand, although this comes with negative impacts on the mechanical properties of the mortar. Nonetheless, these effects can be mitigated when considering their economic and environmental implications.

The coupling effect of calcined layered double hydroxides and impressed current cathodic protection system on chloride ion binding and migration of sea sand mortar

Chloride introduced by sea sand and sea water leads to steel bar corrosion. Calcined Layered double hydroxides (CLDH) and impressed current cathodic protection (ICCP) system were used to adsorb chloride ion and control steel bar corrosion in chloride abundant environment. In this research, chloride binding effect of two kinds of CLDH were investigated in simulated concrete pore solution. Besides, chloride absorption capacity and steel bar corrosion resistance of Mg-Al CLDH was explored in mortar. Further, hydration degree of mortar installed ICCP system and migration of ions around the anode and cathode were detected. Results show that Mg-Al CLDH exhibits excellent chloride binding capacity and corrosion resistance. After installing the ICCP system, corrosion of steel bars in mortar mixed Mg-Al CLDH was controlled. And ions in mortar specimen around anode or cathode exhibits migration phenomenon in different degree. A two stage-four step model was established to explain the degradation of hydration products and ion migration in CLDH-ICCP system. Under the ICCP system, Cl− in pore solution increased at early stage and then decreased both around anode and cathode, the increment process was controlled by desorption of Mg-Al CLDH and decreased process was controlled by degradation of hydration products. Therefore, the CLDH-ICCP system was recommended to solve the problem of steel bar corrosion introduced by marine environment.

Utilization of Granulated Blast Furnace Slag in Cement Mortar: Performance Analysis Against M-Sand

This study aims to explore the feasibility of incorporating Granulated Blast Furnace Slag (GBFS) as a sustainable alternative to manufactured sand (M-Sand) in cement mortar, to enhance both environmental sustainability and mechanical performance. The research involves a systematic investigation where M-Sand is progressively replaced by GBFS at varying levels of 10%, 20%, 30%, 40%, and 50%. The effects of these replacements are evaluated through a series of tests that focus on the mortar's physical properties, as well as its compressive and tensile strengths. Experimental results reveal that replacing 30% of M-Sand with GBFS produces the most favorable outcomes, with the compressive strength of the mortar exceeding that of the control mix by 12% after 28 days. The tensile strength also showed marked improvements at this replacement level. However, when the replacement level exceeds 30%, both compressive and tensile strengths begin to diminish, indicating that excessive substitution may adversely affect the mortar's structural integrity. The findings of this study provide valuable insights into the optimal use of GBFS in cement mortar, demonstrating that a 30% substitution not only enhances strength characteristics but also contributes to more sustainable construction practices by reducing reliance on natural sand resources. This research supports the potential of GBFS as a viable material for improving the environmental profile and durability of cement-based materials.

Microstructural Analysis of the Effect of Using Nano-silica on the Mechanical Properties of Cement–Sand Mortar Under the Effect of Heat

The performance of cement-based materials depends on the characteristics of solid particles at the nano-scale or nanometer porosities in the interfacial transition zone between cement particles and aggregate. Heat significantly affects the properties of these particles and the connection between them. Accordingly, the present study seeks to investigate the effect of nano-silica on the strength parameters of sand–cement mortar at high temperatures. In this regard, the sand–cement mortar was prepared by replacing 5, 10, and 15 percent of cement with nano-silica. The specimens were subjected to temperatures of 25, 100, 200, 400, 600, and 800 °C after curing at the ages of 3, 28, and 90 days. The effect of high temperatures on the physical and mechanical properties of sand–cement mortar was analyzed using macro-structural tests of compressive strength, loss in weight, and water absorption, and microstructural tests of X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results revealed that the macro-structural behavior of sand–cement mortar highly depends on the microstructure and changes in cement nanostructures during heat treatment. Primary portlandite and C–S–H nanostructure were destroyed at 600 °C, and alite, belite, and β-wollastonite were formed at 800 °C. Adding nano-silica improved the strength properties of sand–cement mortar against heat, so the compressive strength of 28-day specimens containing 15% nano-silica increased from 13.9 to 19.2 MPa at a temperature of 800 °C.

Shotcreting with Cement–Sand Mixtures Under the Influence of an Electrostatic Field

One of the primary and still unresolved problems of shotcreting is the high rebound rate of the material, which reaches over 20% in “dry” shotcreting. There is a practical need to improve the very principle of shotcreting and methods for optimizing the movement of torch particles. Materials and Methods: The purpose of this study was to justify the use of the electrostatic treatment of cement–sand mortar in the process of performing shotcreting works using the dry method. It was proposed that the binder and then the finished mixture be ionized step-by-step (by passing it through a non-uniform electrostatic field formed by corona electrodes). As a result, the shotcrete will be held on the fence. Results: Analysis of the modeling results shows that the presence of an electrostatic field slows down the particle and reduces the kinetic energy of the rebound. After theoretical calculations, experiments were conducted, during which, the torch size and the plant productivity were changed, and the rebound mass was weighed. After application to the surface, prototypes were formed and subjected to strength tests. It was determined that gunning in a sharply non-uniform electric field demonstrates its practical and economic efficiency due to the uniform deposition of charged particles on the treated surface and low power consumption. Conclusions: It was established that the electrostatic treatment of a cement–sand mixture during application allows concrete particles to be retained on the shotcrete surface, the rebound of the material to be reduced and the strength of concrete to be increased.

Compressive Strength Characteristics of Compressed Stabilized Earth Block (CSEB) Units and Walls

This paper is mainly focused on compressive strength behavior of Compressed Stabilized Earth Block (CSEB) units and CSEB walls. Compressed Stabilized Earth Block (CSEB) is a rectangular block used in wall construction. The ingredients of CSEB are soil, cement, fine aggregate, crusher dust, and a small amount of water. These blocks have less energy consumption and carbon emission, and they provide improved thermal insulation. In addition, they use local resources and disseminate appealing aesthetics with elegant profile and uniform size. Due to these advantages CSEB can be used as a green construction material. This research aims to study the strength characteristics of CSEB wall in compression and evaluate the suitability of CSEB walls as load bearing walls in structures. This research studies physical and mechanical characteristics of CSEB units made from red residual soil of Lele (Lalitpur) with 8% cement for stabilization. This paper discusses the compressive strength behavior of walls constructed of size 0.660m x 1.100m x 0.220m using CSEB units in cement sand mortar and stabilized mud mortar separately which were tested after 28 days. The experimental values after laboratory testing of CSEB masonry wall with height to thickness ratio 5:1 for cement sand mortar (1:6) and stabilized mud mortar (stabilized with 8% cement and 16% extra sand) separately are compared with relevant values from different codes. Results obtained from compressive strength tests of masonry walls constructed in the laboratory and those values from different codes concerning the strength of masonry unit and mortar are compared and found to be in agreement. The comparison of laboratory results with codal provisions of design of masonry walls illustrate that CSEB masonry walls can be designed in the similar way as brick masonry walls.

Mechanisms for Recycling E-Glass Waste to Enhance The Fracture Energy of 3d Printed Structural Dune Sand Mortar

Mechanisms for Recycling E-Glass Waste to Enhance The Fracture Energy of 3d Printed Structural Dune Sand Mortar

Effects of Mineral Admixtures on the Alkali–Silica Reaction in Granite Manufactured Sand Mortar

Effects of Mineral Admixtures on the Alkali–Silica Reaction in Granite Manufactured Sand Mortar

Utilization of Crushed Waste Glass as a Partial Replacement for Sand in Cement Mortar for a Sustainable Environment

The disposal of non-biodegradable waste glass poses a serious environmental threat as it can cause soil, water, and air pollution when not properly discarded in landfills. The use of glass in construction has shown promising results in enhancing various properties of concrete and improving overall sustainability. This study investigated the mechanical properties of mixed colored glass, comprising green and brown hues, and clear glass in mortar, to explore the feasibility of using colored glass as a replacement for sand and to determine how the addition of color affects the mechanical properties of mortar. The incorporation of waste glass as a partial replacement for sand resulted in a 2.7% increase in flow table values when 5% of Mixed Colored Glass Sand (MCGS) was utilized in place of sand, as compared to the control mix (CM). Conversely, a 5.4% and 4.7% decrease in flow table values were observed when 15% of clear glass (CGS) and MCGS were used as a substitute for sand respectively. When 15% of MCGS and CGS were replaced with sand, compressive strength increased by 60% and 42.6% respectively, compared to the control mix, when 5% MCGS, 10% MCGS, 5 CGS, and 10% CGS were observed. After 28 days of curing, a 10.6% and 10% increase in strength was observed when 10% of MCGS and CGS were replaced. At 7 days, a 3.3% increase in flexural strength was found when 5% of MCGS was replaced with sand was observed. The fire resistance test showed reduced mass and compressive strength of specimens at different temperatures. No significant expansion of ASR was recorded throughout the test period. The use of waste glass as a substitute for sand has shown improvements in environmental sustainability and economics. When 10%WGS and 15%WGS were utilized, 20% and 30% of waste glass sand was replaced with sand, respectively. Incorporating waste glass into construction enhances the mechanical properties of concrete and promotes the conservation of natural resources and environmental sustainability. This study examined the economic advantages of replacing sand with waste glass and found that CM has the highest cost of 90.64 Tl. At replacement of 5%, 10%, and 15% MCGS showed 1.07%, 1.96%, and 2.95% savings compared to the control mix, respectively. Moreover, replacing 5%, and 10% of natural sand with clear glass sand could bring about savings of 1.91%%, and 3.63%, respectively. Replacing 15% CGS showed the highest savings of 5.45% compared to the control mix. The study compared the use of colored and clear glass as a partial replacement for sand and found that there were slight differences in the results, but overall they were similar.

Water and Chloride Ion Transport Characteristics of Unsaturated Aeolian Sand Mortar under Capillary Absorption

Water and Chloride Ion Transport Characteristics of Unsaturated Aeolian Sand Mortar under Capillary Absorption

Unleashing high-volume waste plastic recycling in sustainable cement mortar with synergistic matrix enabled by in-situ polymerization

The substantial energy consumption and CO2 emissions associated with the production and transportation of concrete and its components have necessitated the search for suitable replacements, particularly waste materials such as plastic, to mitigate their environmental impact. The emergent challenge of employing recycled waste plastics (RWP) in concrete centers around their poor interactions with the cement matrix. Here, a synergistic approach with in-situ polymerization by using sodium acrylate (SA) at various doses (0 %, 0.5 %, 1 %, 2 %) was employed to produce environmentally-friendly mortars. Recycled polypropylene (PP) particles were adopted as the aggregate to replace natural sand in cement mortar. Results indicate decreased water contact angel by 46 % and increased pull-off strength by 25 % for SA-polymerized PP. Moreover, mortars with 2 % SA exhibited a 31 % increase in compressive strength, a 64 % increase in flexural strength, a 76 % reduction in water sorptivity, and a 13.6 % decrease in total porosity. The formation of interconnected polymeric networks in the cement matrix and interfacial transition zone (ITZ) contributes to structural densification, highlighting the superior engineering properties. These findings present a promising pathway towards sustainable and resource-efficient building materials, fostering a circular economy for plastics.

The Application of Converter Sludge and Slag to Produce Ecological Cement Mortars.

The paper presents an analysis of the effective use of a mixture of steel sludge (S1) and slag (S2) from the converter process of steel production for the production of cement mortars. Metallurgical waste used in the research, which is currently deposited in waste landfills and heaps near plants, posing a threat to groundwater (possibility of leaching metal ions present in the waste), was used as a substitute for natural sand in the range of 0-20% by weight of cement (each). The obtained test results and their numerical analysis made it possible to determine the conditions for replacing part of the sand in cement mortars with a mixture of sludge and slag from a basic oxygen furnace (BOF) and to determine the effects of such modification. For the numerical analysis, a full quadratic Response Surface Model (RSM) was utilized for two controlled factors. This model was subsequently optimized through backward stepwise regression, ensuring the inclusion of only statistically significant components and verifying the consistency of residual distribution with the normal distribution (tested via Ryan-Joiner's test, p > 0.1). The designated material models are helpful in designing ecological cement mortars using difficult-to-recycle waste (i.e., sludge and converter slag), which is important for a circular economy. Mortars modified with a mixture of metallurgical waste (up to 20% each) are characterized by a slightly lower consistency, compressive and flexural strength, and water absorption. However, they show a lower decrease in mechanical strength after the freezing-thawing process (frost resistance) compared to control mortars. Mortars modified with metallurgical waste do not have a negative impact on the environment in terms of leaching heavy metal ions. The use of a mixture of sludge and steel slag in the amount of 40% (slag/sludge in a 20/20 ratio) allows you to save 200 kg of sand when producing 1 m3 of cement mortar (cost reduction by approx. EUR 5.1/Mg) and will also reduce the costs of the environmental fee for depositing waste.

Assessment of Cement Mortar Strength Mixed with Waste Copper Mine Tailings (CT) by Applying Gradient Boosting Regressor and Grid Search Optimization Machine Learning Approach

Growing environmental concerns and resource scarcity, the construction industry must investigate sustainable materials that reduce waste while improving building material properties. This study investigates the viability of using waste copper mine tailings (CT) as a partial replacement for river sand in cement mortar, assessing the impact on mechanical strength and developing a predictive model using a Gradient Boosting Regressor (GBR) and Grid Search Optimization (GSO). Copper tailings mix designs ranging from 0% to 50% replacement by volume (river sand) were developed, with a constant cement quantity while varying the proportions of sand and tailings. The experiments were carried out at Poornima University in Jaipur, using standard protocols to prepare specimens and measure their compressive strength for 0% CT to 50% CT as volume percent in the mixture. The results showed that the addition of copper tailings up to 20% (3CT2) had highly increased the mortar strength, while mix design 6CT3 showed the best strength at 30% CT. Beyond this threshold, strength declined, thus indicating an optimal replacement level. In the final step of the research, the GBR-GSO-based machine learning approach was employed for developing the predictive model for compressive strength in mortar with different contents of copper tailing for mix types 3CT and 6CT. The predictions obtained by the developed model were in very good agreement with empirical data, thus supporting the potential of machine learning to predict material performance for guiding the use of unconventional additives in construction. It could be said that this work not only represents the material properties of copper-tailing-infused mortar but also showcases state-of-the-art machine learning techniques in the building materials science domain while opening new paths for more innovative and sustainable building practices.

Effect of middle stud on ultimate strength and behavior factor of brick masonry shear wall in cold formed steel frame

AbstractLightweight steel framing is one of the modern construction technology systems. This system is mostly used for low to mid-rise buildings. The lightweight steel framing system has many advantages, including lightness, ease of installation, high execution speed, and being more cost-efficient. Since the manufacturers of cold formed steel frames use bricks in an unprincipled way to cover these structures and because of less laboratory research in this regard, in the present research to principled use of this structure, the effect of the middle stud was evaluated on seismic behavior of brick shear wall in cold formed steel frame with brick face. For this purpose, four cold formed steel frames were made in two different configurations (without middle stud and with middle stud) using cement sand mortar, wire mesh, and brick shear walls. Based on the results, the middle stud would cause weakness in the permissible deformation of the brick walls, and in shear walls without middle stud, deformations occur along with the acquisition of resistance to larger deformations. Accordingly, the presence of the middle stud increases the average shear strength by 30%, and this increase in resistance causes a decrease in the behavior factor and ductility of the walls, which practically indicates the seismic behavior of the frames with the middle stud.

Impact of the partial substitution of cement and sand by ash from several types of wood species in cementitious materials manufacture: valorization in the industrial field

The main objective of this article is to evaluate the potential use of wood ash as a substitute for cement and sand in mortars. Three types of wood were selected: Ayous, Sapelli and Fraké, all of which were sourced from carpentry in Cameroon. The sawdust was dried and combusted to obtain ash, then ground and sieved. Six types of mortar were produced, with cement substitution at 0%, 5%, 10%, 15%, 20% and 25%. The physico-mechanical properties of these substitutions were determined after 7, 28 and 56 days. The results of the cement paste consistency show that it increases with the addition of ash, due to the fact that sawdust ash requires a large quantity of water. The addition of ash caused an increase in setting time due to the fact that sawdust ash is less reactive than Ordinary Portland cement, resulting in a delay in the rate of cement hydration. Apparent density values decreased with the addition of sawdust ash, probably due to the hygroscopic behavior of type of ash in mortar specimens. The highest pozzolanic index is that of 5% replacement by ash and almost identical absorption for all mortars at this substitution percentage. Acid attack results revealed a higher durability of mortar specimens with the higher percentage of ash substitution. Optimum compressive strengths for the different substitution percentages were observed at 5%, 15% and 10% respectively for Ayous, Sapelli and Fraké. The best wood ash is Sapelli because of its chemical composition and resistance to compression in mortars. At 56 days, compressive strength values exceed those of the reference composition. This may be due to pozzolanic reactions in the mortars of ash.

Comparison of the Use of Excavated Soil Recycled Fine Aggregate as a Substitute for River Sand in Mortar Mixing

This study comparatively investigated the performance of mortar prepared using excavated soil recycled fine aggregate (ESRFA), which mainly included fine aggregate obtained by sediment separation equipment and sieving. Scanning electron microscopy (SEM) was used to analyse the size and shape of ESRFA particles. The particle size distribution of ESRFA was uneven and its sphericality was lower than that of river sand. Two series of rendering mortar mixes were prepared using identical water/cement and aggregate/cement ratios of 0.55 and 3, respectively, using river sand as fine aggregate. ESRFA was used to replace 30%, 50%, 70%, and 100% of the river sand in each mixture. The experimental results showed that the flowability of the mortar prepared with ESRFA was lower than that of the aggregate-based mortar, but the porosity, water absorption, and mechanical properties (compressive strength, flexural strength, and drying shrinkage) increased and then decreased upon increasing the ESRFA content. In conclusion, ESRFA shows potential as a partial replacement for river sand in mortar, particularly at lower substitution rates. Further research is needed to optimize the processing and application of ESRFA in concrete to enhance its performance and sustainability.

Investigating correlations between microstructural characteristics and mechanical properties of coral sand mortar with different silica fume contents

The use of coral sand in concrete and mortar for ocean engineering has led to significant reductions in construction costs and improved construction efficiency. However, this approach poses challenges such as low strength, high brittleness, and high porosity. To address these challenges, this study incorporated silica fume to enhance the mechanical properties of the mortar and investigated the effects of different silica fume contents on the hydration process, pore structure, and strength of coral sand mortar. Additionally, this study introduced a novel iterative approach combining low-field nuclear magnetic resonance and scanning electron microscopy image analysis to determine transverse relaxivity (ρ2). During the early hydration process, the intensity spectrum of coral mortar exhibited three peaks at 298, 1841, and 299 au, corresponding to transverse relaxation times (T2) of 0.64, 6.83, and 83.10 ms, respectively. Over a 6 h hydration period, the spectrum of the specimen prepared with white cement exhibited an additional peak that gradually merged with the main peak. As the curing period extended from 7 to 28 days, the porosity of coral sand mortar decreased by 3.77–4.55 %, while the strength increased by 7.43–14.35 MPa across silica fume contents ranging from 6 % to 24 %. With increasing silica fume content, the calcium–silicon ratio of the samples gradually decreased, promoting the formation of more floccus C–S–H gels. Consequently, the sample porosity first decreased slightly. After 28 days of curing, the coral sand mortar containing 12 % silica fume exhibited the highest strength owing to the increased amount of floccus C–S–H gels. These gels gradually filled the pores between the fibrous C–S–H gels, forming a compact spatial reticular structure. This structure mitigated the adverse impact of high porosity on mortar strength.

Reuse of waste rockwool for improving the performance of LC3-based mortars made with natural and recycled aggregates for sustainable building solutions

The objective of this study is to investigate the effect of waste rockwool (RW) addition on the thermo-physical, mechanical, and fire resistance properties of limestone calcined clay cement (LC3)-based mortars. LC3 binder has been produced by replacing 60 wt% of OPC with limestone (LS) powder and metakaolin (MK) at a percentage of LS to MK of 1:2 (wt%). Waste RW was added at various ratios of 1, 3 and 5 % (by weight of binder) into two types of LC3-based mortars made with natural sand (NS) and ferrochrome waste slag (FCS) aggregates with a binder-to-aggregate vol% of 1:3. Upon the addition of 5 wt% of waste RW, significant enhancements of about 19 % and 21 % were obtained for the compressive strength of NS and FCS mortars, respectively, and attributed to the improved physical packing. After exposure to standard fire for 1 h with a maximum applied temperature of 945 °C, residual strengths of about 57.5 % and 63.8 % have been maintained by the sand and FCS-blended LC3 mortars, respectively. Generally, the incorporation of RW led to a slight increase in the thermal conductivity of both types of mortars; however, the FCS-blended LC3 mortar possessed relatively higher increment rates as compared with the sand mortar, which is helpful in improving the thermal performance in hot climate regions. Remarkable improvements in the microstructure characteristics in terms of compactness, uniformity, and interfacial transition zone (ITZ) tightness were attained by RW addition. Lifecycle assessment (LCA) results demonstrated that about 38–45 % lower carbon emission is associated with the designed LC3-based mortars than the conventional OPC mortar.

A contribution to the study of mortars prepared with recycled sand

No one denies that today concrete is the most used material in the field of civil engineering. It is widely admitted that the production of concrete necessitates large quantities of fine aggregates, specifically river sand and crushed sand. Moreover, the excessive exploitation of river sand, which generally causes a multitude of environmental problems, has pushed the majority of governments around the world to issue rules for the purpose of limiting or preventing the illegal extraction of river sand. The present article aims primarily to make a contribution to studying the possibility of replacing natural sand (NS) and crushed sand (CS) with recycled sand (RS) in ternary mortars, at proportions ranging from 20% to 100%. The consistency of the mixtures, the densities in the fresh and hardened state, the compressive strength after 3, 14 and 28 days of hardening, as well as the absorption of water by immersion and by capillarity at 28 days, were determined and discussed. It should be noted that the (W/C) ratio was set at 0.7 for all mixtures. The experimental results showed that recycled sand could be successfully used as an alternative to natural sand, up to a rate of 40%, for the manufacture of ternary mortars without significantly affecting their properties.

Analyzing the long-term effects of e-glass mortar on sustainability and radiation shielding using ANOVA.

Significant investigations were performed on the use and impact on physical properties along with mechanical strength of the recycled and reused e-glass waste powder. However, it has been modeled how recycled display e-waste glass may affect the characteristics and qualities of dune sand mortar. This study investigates the long-term feasibility of using recycled display e-glass waste as a partial substitute for dune sand at varying percentages (5%, 10%, 15%, and 20%). The main focus is on evaluating its effectiveness in radiation shielding, strength properties, and durability for long-term development under the heating environmental process. Statistical analyses, including analysis of variance, are used to assess the significance of factors and their interactions on these characteristics. Additionally, a regression equation derived from the model offers insights into the quantitative relationship between the factors and properties. The results of the experiments led to the conclusion that the most effective proportion of e-glass waste to include in mortar is 20%, with the weight of dune sand. Including e-glass waste, they significantly increased the five characteristics of the mortar, making it suitable for high-strength mortar applications continue up to 68MPa. The ANOVA model used in this study was trained using the same experimental research design and was critical in predicting the properties of the mortar. The model produced an accurate result with an R2 value greater than 0.99. E-glass replacements exhibit remarkable radiation shielding, characterized by pozzolanic activity and superior internal bonding due to its compact texture, contributing to enhanced long-term strength.