Durability Properties Of Cement Mortar Research Articles

Hybrid Effect of Metakaolin and Nano-Silica on Mechanical and Durability Parameters of Mortar

The incorporation of pozzolanic materials such as nano silica and metakaolin in cementitious materials has gained significant attention in recent years due to their potential to improve the mechanical and durability properties of cement-based composites. This thesis investigates the hybrid effect of nano silica and metakaolin on the mechanical and durability properties of cement mortar. The research work involved the preparation of cement mortar specimens with varying proportions of nano silica and metakaolin, which were then subjected to a series of mechanical and durability tests. The mechanical tests included compressive strength, while the durability tests included water absorption and elevated temperature test. The study showed that the addition of both nano silica and metakaolin to cement mortar resulted in a significant improvement in the mechanical properties of the mortar. Additionally, the hybrid effect of nano silica and metakaolin resulted in enhanced durability of the cement mortar, with a significant reduction in water absorption and improved temperature resistance. The findings of this study will have significant implications for the development of sustainable and durable cementitious materials. The use of pozzolanic materials such as nano silica and metakaolin can reduce the consumption of cement and the associated carbon footprint while also improving the durability and long-term performance of cement-based composites. Overall, this study suggests that the incorporation of nano silica and metakaolin can lead to significant improvements in the mechanical and durability properties of cement mortar, making it a promising material for use in various construction applications.

The Mechanical and Durability Properties of Cement Mortars with Different Types of Fibers and Chemical Admixtures

Improving the mechanical and durability properties of cement-based materials such as concrete is very important. The use of fibers is a good alternative in cement-based materials production. This study investigated workability, some mechanical and durability properties of cement mortar in cooperation with glass and basalt fiber. Basalt and glass fibers were used instead of the aggregate in the mixture as 0.8 and 1% by weight. The compatibility of the polycarboxylate-based water reducer and the modified phosphonate-based water reducer as chemical admixtures in selected ratios and fibers was tested. Experiments were carried out after 7 and 28 days of water cure and the effect of the curing periods were also determined. Flexural strength values of basalt fiber reinforced samples in all sets were found to be more than glass fiber reinforced samples. However, high compressive strength are obtained in glass fiber reinforced samples. Beside the positive results obtained in the mechanical properties, the effects of the fibers in the abrasion and acid resistance (10% hydrochloric acid solution during 30 days) have given positive results.

Use of Clay and Titanium Dioxide Nanoparticles in Mortar and Concrete—A State-of-the-Art Analysis

In the past decades, nanomaterials have become one of the focal points in civil engineering research. When added to cement-based construction materials (e.g., concrete), it results in significant improvements in their strength and other important properties. However, the final mix characteristics depend on many variables that must be taken into account. As such, there is no general consensus regarding the influence upon the original material of certain nano-sized additives, the optimum dosage or the synergistic effect of two or more nano-materials. This is also the case for titanium dioxide (TiO2) and nanoclay (NC). The paper focuses on reporting the existing research data on the use of the above-mentioned materials when added to mortar and concrete. The collected data is summarized and presented in terms of strength and durability properties of cement mortar and concrete containing either TiO2 or NC. Both nano-materials have been proven, by various studies, to increase the strength of the composite, at both room and elevated temperature, when added by themselves in 0.5%~12% for TiO2 and 0.25%~6% for NC. It can be inferred that a combination of the two with the cementitious matrix can be beneficial and may lead to obtaining a new material with improved strength, elastic and durability properties that can be applied in the construction industry, with implications at the economic, social and environmental levels.

Mechanical strength and durability analysis of mortars prepared with fly ash and nano-metakaolin

Pozzolans such as fly ash (FA) and nano-metakaolin (MK) are the two industrial wastes that have attracted the attention of researchers due to their pozzolanic action that improves the performance of cementitious materials in an aggressive environment and can reduce global cement demand and lessen the emission of greenhouse gases. This study analyzes the strength and durability properties of cement mortar with partial substitution of cement with MK in the presence of FA. The effect of substitution of MK in binary and ternary blends on strength and durability has been studied by varying the dosage of FA (5‐20%) as well as MK (2.5‐10%) and optimization of MK content has been carried out. A comparative analysis of beneficial aspects of FA and MK, along with their combination in optimized content at a fixed water/binder ratio of 0.5, has also been performed in terms of corrosion resistance through electrical resistivity and half-cell potential measurements. Further, the results have been correlated by microstructural analysis. The study reveals a significant increase in strength and durability of mortar at a dosage of 10% FA+7.5% MK with an increase in chloride, sulfate and corrosion resistance due to improved microstructure owed to the better pozzolanic action of the substituents with synergistic action. Thus, the partial substitution of cement with optimized content of MK (7.5%) in the presence of FA (10%) can not only help in solid waste management but can also reduce the cement consumption leading to sustainable construction.

Effective utilization of textile industry waste-derived and heat-treated pumice powder in cement mortar

A justifiable replacement for pozzolana that utilizes industrial wastes is needed due to the growing concern on CO2 emissions associated with cement. The effect of heat treatment of pumice powder (PP) on mechanical and durability properties of cement mortar was investigated in this study. Nine different mixes of mortars with varying cement replacement levels (10 %, 20 %, 30 %, and 40 %) by weight of PP were prepared. The PP was treated at 100 ℃ (P-100) and 700 ℃ (P-700). Strength activity index (SAI), water demand, setting time, and flow characteristics were determined. Mechanical properties and porosities were also measured and determined at the age of 7, 28, 56, and 90 days. Moreover, mortar samples were exposed to acidic media for 120 days to assess durability. Results of the SAI showed that the high pozzolanic potential of P-700 is attributed to amorphous silica (SiO2) and detected in the X-ray diffraction test. The PP content showed a positive effect on setting times and flowability of mortars. Moreover, 20 % replacement at all ages achieved maximum mechanical properties while 30 % replacement at later ages improved the mechanical properties compared with the control mix. Notably, high replacement levels of PP enhanced the resistance against acidic attack. The SEM-EDX analysis along with Thermogravimetric Analysis (TGA) test verified the better performance of P-700 over P-100.

Enhanced Mechanical and Durability Properties of Cement Mortar by Using Alumina Nanocoating on Carbon Nanofibers.

This study evaluated the effect of carbon nanofibers (CNFs) coated by aluminum oxide Al2O3 as a reinforcement on compressive strength, frost resistance, and drying shrinkage of cement mortars. Three weight ratios of 0.125%, 0.25%, and 0.5% of Al2O3/CNFs and bare CNF cement mortars were compared with reference cement mortar samples. The reactive porous and high surface area layer of alumina induced the hydration reaction and promoted the production of well-distributed hydration gel. Derivative thermal analysis–differential thermogravimetric (TGA-DTG) and X-ray powder diffraction (XRD) characterization showed that Al2O3/CNFs reinforcement led to greater hydration gel production than bare CNFs. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were performed to study the coating and microstructure of the cement mortars evaluated in this paper. The results show that the optimum enhancement of the cement mortar properties was obtained at ratios of 0.125% for Al2O3/CNFs and 0.25% for CNFs. This enhancement was greater with Al2O3/CNFs-reinforced specimens in terms of high compressive strength, less compressive strength degradation after 150 cycles, and less drying shrinkage. The low use of the CNFs in Al2O3/CNFs samples indicates the coating is an economical and promising approach for improving the performance of cement mortars.

Influence of marine sand as fine aggregate on mechanical and durability properties of cement mortar and concrete

Concrete is commonly manufactured using river sand and manufactured sand (M-Sand) as fine aggregates. As river sand has more scarcity, M-Sand is now the preferred fine aggregate. For reduce the consumption and extraction of natural aggregate (river sand), this paper presents washed marine sand (MS) as an alternative fine aggregate that can replace M-Sand. The purpose of this research is to examine the mechanical, micro-structural and durability properties of concrete and cement mortar made with MS as a fine aggregate in partial replacement of M-Sand from 20% to 100%. For better understanding the characteristics of MS and M-Sand, physical properties of MS and M-Sand, as well as the chemical properties of washed and unwashed marine sand are compared. The experimental tests for mechanical properties of compressive strength, elastic modulus, split tensile strength and flexural strength, durability properties of RCPT, sorptivity, acid resistance, alkali attack and water absorption are investigated for cement mortar and concrete. According to this result, 60% of MS meets the desired durability and strength properties. Furthermore, microstructural properties such as EDX and SEM analysis are also carried out to further verify that MS as an alternate fine aggregate.

Effect of graphene oxide and nano silica on mechanical and durability properties of cement mortar

Nowadays, nano-technology has already influenced many fields, including civil engineering also. Cementitious composites contain various nanomaterials that have considered as novel materials with improved microstructure, mechanical and durability properties. Recently graphene oxide and nano silica have appeared as the most promising nano-materials for civil engineering applications. However, graphene oxide and nano silica addition in the cement mortar improves the compressive strength, split tensile strength and flexural strength. Ultra-high resolution field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) analysis are used to see the fracture surface of samples containing 0.07% GO and 4.5% of NS to the weight of cement indicated that GO and NS flakes were well dispersed in the cement mortar matrix and no aggregates were observed. The compressive, bending, and split tensile strength of cement mortar, which contains 0.07% GO and 4.5% of NS by weight of cement after 28 days of curing, is raised by 22.25%, 38.77%, and 10.25%, respectively, as compared to regular cement mortar. These durability studies, such as acid resistance and salt resistance, the weight loss was found in acid, and salt immersion addition of GO&NS shows good resistance in the cement matrix. In addition, SEM analysis has shown the growth of calcium silicate hydrates (C-S-H Gel) in GO and NS cement mortar has compared with normal cement mortar.

Influence of nano-silica on early age and durability properties of cement mortars

This paper investigates the performance of cement mortar with the addition of various percentages of nano-silica (3%, 5% and 10%) at constant water-to-cement ratio. Early age properties of mortar along with the hydration mechanism were determined using flow test, setting time test, micro calorimetry and thermo-gravimetric analysis tests. In addition, hardened and durability-related properties using migration resistance and thermal conductivity tests were evaluated. It was observed that the workability and the setting time decreased largely according to the increase in the percentage of nano-silica as compared to the reference mortar. This finding is confirmed by micro calorimetry results, which indicate a significant increase for the heat evaluation in the presence of nano additives. The thermo-gravimetric analysis indicated the acceleration of the hydration reaction and continuation of the prolonged pozzolanic reaction, which results in the densification of the microstructure confirmed by the increase of compressive strength by 21% at 112 days for 10% addition of nano-silica as compared to the reference mortar. Moreover, the incorporation of nano-silica had also improved the durability of the mortars by reducing the effective diffusion coefficient and thermal conductivity by 46% and 40%, respectively, especially for mortar containing 10% nano-silica.

Mechanical and durability properties of cement mortar and concrete reinforced with glass micro fibre

Mechanical and durability properties of cement mortar and concrete reinforced with glass micro fibre

Effects of Reclaimed Asphalt Pavement aggregates and mineral admixtures on pore structure, mechanical and durability properties of cement mortar

Abstract The study evaluate the feasibility of fine fraction of Reclaimed Asphalt Pavement (RAP) aggregates in cementitious mixes. In order to understand the true effect of fine RAP aggregates in cementitious mixes, cement mortar specimens were casted in place of concrete mixes. The natural fine aggregates were partially replaced by RAP aggregates at 25%, 50%, 75% and 100% by volume. In addition to that, cement was partially replaced by mineral admixtures like silica fume and activated sugarcane bagasse ash. The RAP inclusive cement mortars did showcase satisfactory performance in terms of strength and durability. The characteristic compressive strength and commendable flexural strength were achieved by cement mortars with RAP aggregates. Interesting results were observed for resistance against sulfate attack for RAP inclusive cement mortars where gain of strength was obtained for 25% and 50% replacement mixes even after 90 days of sulfate attack. This behavior was replicated by mineral admixture mixes with similar RAP percentage levels. The gain as well as loss in strength due to sulfate attack was substantiated using pore structure characteristics obtained by Mercury Intrusion Porosimetry (MIP). Analysis of data obtained from MIP supports the presence of entrained air in RAP mortars which suggests qualitatively that cement paste is being protected from frost damage and salt decay. This is an initial study and the same shall be replicated for concrete mixes in near future.

Effect of controlled environmental conditions on mechanical, microstructural and durability properties of cement mortar

Environmental conditions, such as temperature and relative humidity, impact the rate of evaporation, mechanical properties and durability of concrete. Thus, they have a direct effect on the development of transport properties. The purpose of this study is to investigate the effect of controlled environmental conditions on moisture retention, dielectric constant (DC), compressive strength, shrinkage, water sorptivity index, rapid chloride migration test (RCMT), microscopical analysis (thin sections) and electrical resistivity. The mortar specimens were prepared using Ordinary Portland Cement with two water-to-cement ratios of 0.42 and 0.52. The specimens cured in the controlled environments of 25, 46 and 65 °C for temperature, and 30% and 90% for relative humidity. The results showed that curing under higher temperature cause reduction in compressive strength and increase in the sorptivity index. Moreover, a great correlation between DC measurements and sorptivity, the RCMT and electrical resistivity was found. Higher relative humidity helped the performance of samples, considering the durability and mechanical properties.

Effect of Nanoparticles on Strength and Durability Properties on Cement Mortar

The nanotechnology provides an impact on construction industry materials with new properties and produce material with better performance. This paper presents the experimental investigation on the effects of nano particles incorporated in the cementitious materials to study the strength and durability properties of cement mortar. Nano particles such as nano alumina (NA), nano ferric oxide (NF) and nano silica (NS) were mixed at different proportions of 0.5%, 1% and 1.5% by weight of binder in single and binary combinations. Mechanical properties such as compressive strength and split tensile strength; durability properties such as water absorption and rapid chloride permeability test were tested as per standards. The results showed that 1.5% of the combination of nano silica & nano ferric oxide (NSF) and nano silica & nano alumina (NSA) particles increased the mechanical strength and durability properties of cement mortar. The microstructure characteristics results revealed that the nano particles incorporated cementitious materials showed the voids were filled up with nano particles. It acts as filler in cement mortar that enhanced a dense microstructure, reduced the quantity and size of calcium hydroxide and also filled the voids of C-S-H gel structure.

RETRACTED: Microstructure and durability properties of cement mortars containing nano-TiO2 and rice husk ash

Abstract In the present study, Compressive strength, water absorption, electrical resistivity, Rapid Chloride Permeability Test (RCPT) and Ultrasonic Pulse Velocity (UPV) tests of the hardened composites incorporating two supplementary cementitious materials: agricultural waste ash namely as rice husk ash (RHA) and nano-TiO2 (NT) in cement mortars were investigated. The interfacial transition zone (ITZ) and the microstructure were studied by using Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD) analysis, respectively. Compressive strength results showed a substantial improvement in samples containing NT and also a slight increase in mortar performance was observed by using up to 10 wt% of RHA as a replacement of cement. However, binary mixtures displayed the best results for strength development and durability. It is also seen that a combination of 15% RHA and 5% NT in mortar led to a positive contribution to durability properties. XRD analysis showed that intensity of Alite and Belite phases decreased and new peak of portlandite achieved with the addition of NT. The SEM micrographs illustrated the widespread distribution of mortars containing NT with packed pore structures which resulted in promoting of strength and durability of specimens. Consequently, the combined mixture of RHA and NT has led to the enhancement of strength and durability properties of mortars. In general, it seems that 15% RHA and 5% NT can be considered as a suitable replacement regarding to the economic efficiency and hardened properties.

Study on Strength and Durability Properties of Cement Mortar with Chemical and Thermal Activation of Clay

In this paper, the consequence of clay on the strength and durability properties of the cement mortar has been looking into with thermal and chemical activation of clay as a partial replacement of cement in mortars. The clay can be chemically activated with 0.25M NaOH solution, and thermal activation is 800°C for one hour. The replacement levels of cement by 0% to 20% with an interval, 2.5% weight of cement for thermal and chemical activated clay were taken for the study. The mechanical and durability properties such as Compressive Strength, Flexural Strength, saturated water absorption, and chloride ion penetration of the clay mortars examined at the age of 28days. It was found that the strength of the cement mortar significantly increased by using thermal and chemical activated clay. The clay replacement was found to be 2.5% in the presence of 0.25M NaOH solution and thermal activation. The result of this investigation exhibits significant improvement in mechanical and durability properties with evident from XRF, FTIR, strength and FESEM.

Morphological, Mechanical and Durability Properties of Cement Mortar Reinforced with Multi-Walled Carbon Nanotubes

Morphological, Mechanical and Durability Properties of Cement Mortar Reinforced with Multi-Walled Carbon Nanotubes

Effect of Colloidal Nano-Silica on the Mechanical and Durability Performances of Mortar

s. The mechanical and durability properties of cement mortars with colloidal nanosilica (CNS) were investigated experimentally. Reference mortar with a low water-to-cement ratio of 0.30 was used in this study. The influence of CNS was evaluated by adding 0.5, 1.0, 1.5 and 2.0% of CNS by weight of cement. CNS was first stirred in the mixing water for 2 minutes before added to cement and sand. Superplasticizer was used to maintain the same flowability. Results showed that the compressive strength consistently increases with higher dosage of CNS at all the curing ages, due to both hydration acceleration and pozzolanic reaction. With the increase in CNS, the migration coefficient and water sorptivity consistently decreased; with 2% of CNS, the migration coefficient and water sorptivity were reduced by 45% and 30% respectively in comparison with the reference mortar. The improved durability could be explained by the reduction and refinement in the porosity, which can be attributed to nanofiller effect and pozzolanic reaction of nanosilica. Furthermore, the addition of CNS could reduce the drying shrinkage by densifying the microstructure in the cement paste, which has not been reported previously.

Effect of acrylic fibres geometry on physical, mechanical and durability properties of cement mortars

This paper presents the results of an experimental investigation to verify the feasibility of using acrylic textile fibre to improve cement based mortars properties. The assessment of acrylic fibres influence on mortars properties was performed comparing the physical, mechanical and durability behaviour with mortars produced using glass and polypropylene fibres. The influence of the mixing procedures was also investigated. Effects of acrylic fibre aspect ratio ( l/ d) and volume fraction ( V f) on mortar bulk density, compressive strength, flexural strength, water absorption and plastic shrinkage were investigated. For this purpose, acrylic fibres having six different l/ d ratios 93, 148, 222, 278, 444 and 833 were used and the volume percentage of fibres were added to mortar mixes was of 0.2%, 0.5% and 1.0%. The mortar plastic shrinkage was also studied on slabs casted with 0.5%, 0.2%, 0.1% and 0.05% acrylic fibres volume. It was found that acrylic fibre reinforced mortars have physical, mechanical and durability related properties similar to the mortar reinforced with glass or polypropylene fibres. These results indicate that there is a potential technical feasibility of using this type of fibres in cementitious composites.

Mechanical and durability properties of cement mortar with Algerian natural pozzolana

This paper presents a study of the properties and behaviour of cement mortar with natural pozzolana from Algeria. The effect of level of addition of natural pozzolana (0, 10, 20, 30, and 40%) on the mechanical properties of mortars at different ages as well as the effect of curing environment and the period of initial curing on the mechanical properties were investigated. The performance of natural pozzolana cement exposed to three aggressive solutions (acids, sulphate, and chloride) is also analysed. The results indicate that the strength of pozzolanic cement is lower than that of plain Portland cement at early ages, but can reach the same order of strength at longer curing periods. The enhancement of the resistance to acid and sulphate attack as well as to chloride ion penetration of natural pozzolanic cement is also demonstrated.