Water Absorption Of Concrete Research Articles

Study of the Structure and Properties of Concrete Modified with Nanofibrils and Nanospheres

The application of modifying nanoadditives in the technology of cement composites is currently a relevant and widely researched topic in global materials science. The purpose of this study was to investigate new nanoadditives—nanofibrils made from synthesized wollastonite (NF) and nanospheres from corundum (NS)—produced by LLC NPK Nanosystems (Rostov-on-Don, Russia) as a modifying additive. During the experimental investigations, the mechanical properties of cement pastes and concrete were examined. This included an analysis of the density, compressive and bending strength, as well as water absorption of concrete that had been modified with NF and NS additives. X-ray phase and microstructural analyses of concrete were performed. It was established that modification of cement composites with NF and NS additives had a beneficial effect on their properties, and the optimal amount for both types of additives was 0.3% by binder weight. The highest recorded enhancements in compressive and flexural strength of concrete with 0.3% NF were 7.22% and 7.04%, respectively, accompanied by a decrease in water absorption by 4.70%. When modifying concrete with 0.3% NS, the increases in compressive and flexural strength were 2.71% and 2.48%, and water absorption decreased by 1.96%. Modification of concrete with NF and NS additives did not have a significant effect on the change in concrete density, which was no more than 1%. Based on the results of phase analysis, it was established that concrete with NF and NS additives were characterized by the presence of five main phases: quartz, portlandite, calcite, larnite, and olivine-Ca. It was found that compositions with 0.3% NF and NS differed from the control composition by the presence of such a phase as olivine-Ca. Microstructural analysis confirmed the effectiveness of NF and NS additives. The microstructure of the modified concretes was distinguished by the extensive occurrence of clusters composed of calcium silicate hydrate zones. The conducted studies prove the possibility of using NF and NS as modifying nanoadditives in the technology of cement composites. The addition of nanofibrils from synthesized wollastonite is the most effective and promising and is recommended for use in real construction practice.

Effect of costus lucanius bagasse fibre on fresh and hardened concrete using RSM modelling

This investigation purposes to use the recycling waste materials in concrete to produce a sustainable environment for construction. The Costus lucanius bagasse fiber (CLBF) was utilized as supplementary cementitious material (SCM) to analyse the workability and mechanical properties of blended cement concrete. The concrete samples were made with the inclusion of 5–20% of CLBF at several w/c ratio by applying RSM modelling and optimization. Moreover, the cubical specimens were cast to study the compressive strength (CS), while beams were used to investigate the flexural strength (FS) on 28th days correspondingly. The outcomes show that the compressive and flexural strengths were decreased with rise in proportion replacement in concrete at various w/c ratio. The highest flexural and compressive strengths was attained at 5% of CLBF at 28 days respectively. Across the tested specimens, the values of compressive strength and flexural strength ranged from 30.20 to 53.92 N/mm2 and 2.15–8.81 N/mm2 for CLBF correspondingly. Besides, the workability and water absorption of concrete is getting decreased as the content of CLBF increases while it is recorded increasing as w/c ratio increases from 0.20 to 0.40. Furthermore, response model predictions were constructed and verified applying ANOVA at an acceptable level of significance of 95%. The coefficients of R2 for the mathematical models ranged from 98 to 99.99%. The research study also indicated that cement can be substituted by CLBF in the production of concrete for various construction purposes.

Study on the evolution of concrete pore structure and moisture transfer mechanism after high temperature based on different sequence NMR technology

This study investigates the influence of elevated temperatures on concrete's pore structure and moisture transfer mechanisms. Concrete samples exposed to temperatures of 200℃, 400℃, 600℃, and 800℃ were subjected to capillary water absorption (CWA) tests, and their properties were analyzed using Scanning Electron Microscopy (SEM) and Nuclear Magnetic Resonance (NMR) techniques employing different sequences (CPMG and SE-SPI). The results reveal after high temperature four distinct categories of pores within the concrete: micropores, mesopores, capillary pores, and macropores. Mesopores are in the highest abundance, followed by capillary pores, macropores, and micropores. As temperature increases, hydration reactions lead to an upsurge in micropores and a decline in the proportion of other pores. With further temperature escalation, the cement slurry's volume alteration causes pore expansion, resulting in a rise in capillary pores and macropores and a decrease in micropores. Furthermore, NMR technology, employing CPMG sequences, identifies three stages in the concrete's CWA process: rapid moisture transfer, moisture transfer rate descent, and moisture transition stage. SE-SPI sequence-based NMR results show that, following high-temperature exposure, moisture transfer within concrete progresses as follows: initially, water rapidly permeates mesopores and capillary pores from the exterior. As CWA time increases, these pores tend to saturate, and water gradually infiltrates micropores and macropores. High temperatures significantly impact the CWA process, enlarging pore sizes and altering the type of pore filling during capillary water absorption in concrete.

Effects of Particle of BA, CMA and FA on Water Absorption of Concrete

The porosity of concrete is the root cause of durability problems in concrete. Water absorption rate and water absorption speed can be used to detect the pore structure distribution of concrete. Based on the principle of permeability coefficient method, the water absorption method was improved in this study. This paper conducted an experimental study on how BA (biomass ash), CMA (cattle manure ash), and FA (fly ash) with different particle sizes affect the water absorption speed and coefficient of concrete. The results showed that among BA, FA, and CMA, the water absorption speed and coefficient of FA are the smallest among all admixtures in concrete, and the water absorption speed and coefficient of BA are the smaller. The water absorption coefficient is greater than that of FA, and the water absorption speed and coefficient of CMA are greater than those of BA. With the same dosage (15% in this test), the smaller the water cement ratio, the smaller the water absorption rate of CMA concrete; The water absorption rate of CMA concrete decreases with the increase of age. When the dosage is the same, the influence of particle size on the water absorption coefficient of concrete is the same as the influence of particle size on the water absorption speed of concrete. Factors affecting the water absorption coefficient of CMA materials include particle size distribution, shape, specific surface area, and so on. The results provide a reference for studying the durability of CMA concrete.

Performance of graphene oxide as a water-repellent coating nanomaterial to extend the service life of concrete structures

Surface treatments help to protect the built heritage against damage (environmental, accidental, etc.), reducing repair and restitution costs and increasing the useful life of building materials. The use of nanomaterials is currently the most important field of research in surface treatment technology for the preservation of building materials and, more specifically, to improve their durability and prevent their deterioration, extending their useful life. This paper studies the influence of a graphene oxide (GO) suspension as a surface treatment on the properties of concrete. The results indicate that, at best, surface treatment with GO can decrease both the water absorption and capillary absorption of concrete by about 15 %. The increase in the amount of GO deposited as a surface treatment leads to a further reduction in concrete water absorption. It is shown that, at best, GO coating also reduces water penetration at low and high pressures by approximately 20 % and 60 %, respectively. In addition, scanning electron microscopy analysis shows that GO surface treatment facilitates the hydration process and densifies the concrete microstructure. A simple aqueous suspension of GO is revealed as a tool with a high potential to protect concrete surfaces in a fast and cost-effective way, thanks to the easy application by spraying and the small amount of material needed to obtain great results.

Potential of Gypsum Waste as a Substitution and Filler Material in Concrete Manufacturing

Gypsum is a dental and construction material that used only at certain times. Gypsum waste can be mixed with food waste so that it endangers the environment. The gypsum waste needs to be separated and recycled. This study examines the potential use of gypsum waste as substitute and filler material in concrete manufacture, including: gypsum characteristic based on XRF, concrete maximum load, concrete compressive strength, concrete water absorption and heavy metal concentration analysis. Gypsum compositions used is 0%, 10%, 20%, 30%, 40% and 50%. The gypsum characterization results showed that there was 98.92% oxide, gypsum was included in type III gypsum, heavy metals such as: Fe = 10 ppm and Al = 16500 ppm, metallic elements such as: Si = 1950 ppm, Ca = 182900 ppm, Mg = 4560 ppm, K = 2200 ppm, and non-metallic elements namely: P = 580 ppm. The highest and lowest of maximum load and concrete compressive strength in the gypsum use as substitute and filler material are produced at the addition of 50% and 10% gypsum, respectively. The gypsum addition as substitute or filler material reduces the concrete water percentage. The heavy metals concentrations resulting from the 28-day-old concrete immersion were: Fe = <0.084 ppm and Al = <0.156 ppm.

Improvement of ornamental stone wastes as sand replacement in concrete using silane coupling agent

This study investigates the replacement of fine aggregates in concrete with untreated and silane-treated marble and granite waste (MGW) in different ratios of 3 wt.-%, 5 wt.-%, 10 wt.-% and 30 wt.-%. Fresh, mechanical, durability, microstructural, and synergistic properties of all concrete mixtures were assessed by conducting slump test, compressive strength test, water absorption test, and Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) analyses, respectively. The results illustrated that mixtures with untreated MGW aggregates achieved a maximum reduction of 58 % in their water absorption when replacing sand with 3 wt.-% MGW, while a maximum reduction of 30 % in the water absorption of concrete was achieved when replacing sand with 30 wt.-% treated MGW. Moreover, all mixtures with MGW (treated and untreated) showed an improvement in their compressive strength at 28 days compared to the control, where a maximum increase of 20 % was achieved when replacing sand with 5 % silane-treated MGW. Microstructural and synergistic analyses revealed that mixtures with untreated MGW appeared to develop fewer microcracks, less distribution of hydration crystals (i.e., ettringite), and higher content of C–S–H than the control. In addition, as appeared in the SEM analysis, the incorporation of treated MGW into concrete resulted in the formation of microcracks that are more noticeable and prominent than the microcracks that were formed in concrete with untreated MGW.

Optimising concrete containing palm oil clinker and palm oil fuel ash using response surface method

Cement production led to the consumption of high energy and generated harmful gases, such as CO2. Therefore, the use of alternative materials becomes necessary. The research attempts to use palm oil clinker (POC) and ultrafine palm oil fuel ash (UPOFA) as a full replacement of coarse aggregate and partial cement replacement, respectively. This study aims to use the response surface method (RSM) to optimise the properties of concrete, namely, density and water absorption. The study investigated the density and water absorption of concrete using RSM. Results showed that the density reduced sharply owing to the full replacement coarse aggregate by POC aggregate. Meanwhile, water absorption increased significantly due to the rise in the POC aggregate replacement. However, water absorption decreased because of the use of UPOFA as cement replacement. The study recommended the use of more UPOFA as cement replacement because of its high pozzolanic property.

Utilisation of raw oil shale as fine aggregate to replace natural sand in concrete: Microstructure, surface chemistry and macro properties

This study set out to examine the unconventional use of raw oil shale (OS) as fine aggregate in concrete instead of its traditional utilisation as a pollutant energy source aiming to hinder the depletion of natural resources. Oil shale particles have been used to replace sand in concrete with 30 wt.-% and 50 wt.-% ratios. Part of the used OS particles was treated with silane prior to their addition in concrete. The fresh, mechanical, and durability properties, along with the micro-properties and surface chemistry of mixtures, were analysed by running the slump, compressive strength, permeability, scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FTIR) tests, respectively. Five concrete mixtures consisting of 30 samples with the size of 150 mm x 150 mm x 150 mm were prepared to serve the testing programme of the study. The results revealed the formation of a well-bonded interfacial transition zone between untreated OS particles and the cementitious matrix due to the presence of pozzolanic materials in OS. However, micro cracks and enlarged capillary pores were witnessed in treated OS mixtures along with a weak interfacial transition zone between the treated OS and the cementitious matrix. Moreover, the use of 30 wt.-% untreated OS reduced the water absorption of concrete by 9% (absorption rate of 9.5%), while other mixtures experienced an increase in their water absorption with a maximum increase of 42% when using 50 wt.-% treated OS (absorption rate of 10.7%). All mixtures attained a reduction in their compressive strength compared to control sample when employing treated and untreated OS in concrete, with a minimum reduction of 13% when using 30 wt.-% untreated OS (compressive strength of 26 MPa). The strength reduction in untreated OS mixtures is due to the formation of free CaO and free SiO2, which promote concrete expansion. The interference between silane and kerogen in OS was the main reason behind the strength reduction in treated OS mixtures. However, this reduction in mixtures’ strength is considered minimal, allowing for their potential use in different construction applications like rigid pavement.

Transport properties of moisture and ionic chelators in concrete

The transport properties of moisture and ionic chelators in the concrete affect not only the durability of the concrete, but also the effectiveness of the repair material in repairing cracks in the concrete. The transport of water and ionic chelators in the concrete was investigated by capillary absorption tests and ICP-OES (Inductively Coupled Plasma Optical Emission Spectrometer). It was found that the smaller the radius of the capillary pore within the concrete, the longer it takes to saturate it with water.The different pore sizes of capillaries take different times to reach saturation, which is one of the reasons for the “square root shift phenomenon” of capillary water absorption in concrete. The higher the initial concentration, the easier it is for the ion chelators to be transported inside the concrete within a certain transport depth range. However, after a certain range of transport depth, the initial concentration does not have a significant effect on the transport of the ion chelators. This is not the same as the transport pattern of nonchelated ions. Comparing the transport processes of chelated and non-chelated ions within the concrete, it was found that chelated ions form aggregation zones when transported within the concrete. The analysis suggests that the repair of pores and cracks within the concrete by the chelating agent promotes the creation of aggregation zones. Other factors such as the presence of chelated ions, the transport medium, changes in porosity, and wet and dry cycles can all influence the formation of chelated ion aggregates.

Effects of Percentages and Effective Cementitious Coefficient of Zeolite and Silica Fume on the Compressive Strength and Water Absorption of Concrete

Effects of Percentages and Effective Cementitious Coefficient of Zeolite and Silica Fume on the Compressive Strength and Water Absorption of Concrete

Compressive Strength of Concrete Containing Roof Tile Waste as Partial Fine Aggregate Replacement

Roof tile waste is one of the wastes which usually generated during construction and demolition activity. It is then disposed at landfill and causes environmental pollution. Rising concrete production pushes for larger quantity of sand to be harvested from river. Excessive sand mining harms the environment and affect the water quality. The approach of using roof tile waste as fine aggregate replacement in concrete would lead to a cleaner environment and more sustainable river ecosystem. This study investigates the influence of crushed roof tile waste on the workability, compressive strength, and water absorption of concrete. A total of five concrete mixes containing various proportion of crushed roof tile waste as partial fine aggregate replacement were prepared. The percentage of crushed roof tile waste used as partial fine aggregate replacement is 0, 5, 10, 15 and 20 by weight of sand. The concrete mixes were subjected to slump test, compressive strength test and water absorption test. The workability of concrete reduced when a larger amount of waste roof tiles was substituted as fine aggregate. The use of 40% roof tile waste as partial fine aggregate replacement increases the concrete strength. Concrete mix that contains roof tile waste exhibits lower water absorption than control concrete specimens and it can be classified as good quality concrete. Conclusively, the integration of roof tile waste would reduce burden at landfill and also lower down the dependency of concrete industry on river sand supply.

Influence of Aeolian Sand on Capillary Water Absorption of Concrete Under Freeze–Thaw Conditions

Aeolian sand (AS) can become a green resource for concrete after the reasonable utilization. Study the evolution of AS concrete (ASC) capillary water absorption (CWA) under freeze–thaw (FT) conditions is of great significance for its popularization and application. One-dimensional (1D) CWA test was performed to analyze the effects of AS and freeze–thaw cycling (FTC) on concrete water absorption characteristics. Pore relative saturation (PRS) and pore saturation were defined to reveal the influence mechanism of AS content on concrete water absorption under FT conditions and predict the moisture distribution in damaged ASC combining with the capillary mechanics theory. The results showed that concrete frost resistance increased with increased AS content and the optimal frost resistance achieved with 100% AS replacement despite its low strength. The initial water absorption rate (WAR), pore saturation, and saturation speed of the ASC decreased with increased AS, while the PRS increased with low AS content but decreased with excessive AS. The water absorption depth increased with increased mass and dynamic elastic modulus loss rates. The mechanism regarding why excessive AS improved concrete frost resistance lay in its internal pore structure and large pore ratio, which reduced pore content that can easily absorb water, enclosed a higher volume of air bubbles, and easily formed "air locking," thereby increasing water transmission resistance and forming long transmission paths during the process of CWA.

Rubber micro granules affect water absorption and compress the strength of concrete composite

End-of-Life cars and trucks Tyres (ELT) are still an environmental issue around the world and in Latvia. The addition of rubber additives into concrete is quite well-studied worldwide. It is known that the introduction of rubber crumb in large quantities (> 5 % by volume) reduces the mechanical strength of the material and the modulus of elasticity. The results have shown us differences between rubber crumb practical size, and the amount of admixture in concrete. Achieved results clearly showed us the difference between shredded rubber micro granules and disintegrated-like admixture particles to achieve the composite concrete water absorption differences in 0,6 % but compress strength in greater diapason.

Experimental evaluation on behavior of poly propylene fiber-reinforced concrete containing Poly Carboxylate Ether and E205 additives

Corrosion is a critical challenge that reinforced concretes are facing that need to be addressed considering environmental circumscriptions. This research investigates various characteristics of polypropylene fiber-reinforced concrete experimentally. Six contents of chemical admixtures are investigated regarding rapid chloride permeability, water absorption, electrical resistivity, and compressive strength. Moreover, quantitatively, the energy-dispersive X-ray microanalysis is employed to specify the cementitious matrix’s chemical compositions. Correspondingly, the cementitious matrix’s chemical mechanism is analyzed by utilizing X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and X-ray Fluorescence (XRF) analysis methods. The results indicate that a minor increment in the content of chemical admixtures decreases chloride permeability, while an increase results in an electrical resistivity up urge. Furthermore, the experimental results demonstrate that specimens with polypropylene fiber and polycarboxylate ether perform better than specimens containing polypropylene fiber and E205 in compressive strength. It has been discovered that specimens, including Poly Carboxylate Ether, demonstrated lower water absorption than the levels observed in specimens with E205. According to test results, it can be concluded that the durability and compressive strength of fiber reinforced concrete with polypropylene fibers are increased by the addition of chemical admixtures. • Adding polycarboxylate ether and E 205 to PPFRC, increases the concrete’s resistance. • Polycarboxylate ether and E205 reduce cracks in PPFRC. • Adding polycarboxylate ether and E205 to PPFRC reduces concrete water absorption.

Thermal and mechanical properties of concrete containing porcelain ceramic tile waste as fine and coarse aggregates

Sustainable development relies on efficient energy consumption and environmental protection. The construction industry accounts for a significant portion of global energy consumption. Concrete, as the most commonly used construction material, can play an important role in reducing global energy consumption owing to its thermal properties and its capacity for using waste materials as mix ingredients. In this study, the use of porcelain ceramic tile waste (PCTW) as a replacement for natural fine and coarse aggregates in concrete, both individually and in combination, was investigated. The thermal conductivity, compressive strength, density and water absorption of concretes made with PCTW aggregate were investigated in a series of novel experiments using 77 specimens prepared from 11 concrete mix designs. Compared with conventional concrete, it was found that the use of non-recyclable porcelain waste reduced the heat penetration rate by about 10.8°C, reduced the thermal conductivity by 38% and increased the compressive strength by 42%.

Durability of Construction and Demolition Waste-Bearing Ternary Eco-Cements.

In recent years, the development of ternary cements has become a priority research line for obtaining cements with a lower carbon footprint, with the goal to contribute to achieve climate neutrality by 2050. This study compared ordinary Portland cement (OPC) durability to the performance of ternary cements bearing OPC plus 7% of a 2:1 binary blend of either calcareous (Hc) or siliceous (Hs) concrete waste fines and shatterproof glass. Durability was measured further to the existing legislation for testing concrete water absorption, effective porosity, pressurized water absorption and resistance to chlorides and CO2. The experimental findings showed that the 7% blended mortars performed better than the reference cement in terms of total and effective porosity, but they absorbed more pressurized water. They also exhibited lower CO2 resistance, particularly in the calcareous blend, likely due to its higher porosity. Including the binary blend of CDW enhanced chloride resistance with diffusion coefficients of 2.9 × 10−11 m2 s−1 (calcareous fines-glass, 7%Hc-G) and 1.5 × 10−11 m2 s−1 (siliceous fines-glass, 7%Hs-G) compared to the reference cement’s 4.3 × 10−11 m2 s−1. The siliceous fines-glass blend out-performed the calcareous blend in all the durability tests. As the mortars with and without CDW (construction and demolition waste) performed to similar standards overall, the former were deemed viable for the manufacture of future eco-efficient cements.

Effects of microbial strains on the mechanical and durability properties of lightweight concrete reinforced with polypropylene fiber

This research investigated the impact of calcium carbonate precipitation induced by the activity of four microbial strains known as Sporosarcina pasteurii, Bacillus megaterium, Sporosarcina ureae, and Bacillus licheniformis at cell concentrations of 107 cells/ml on lightweight fiber concrete (LWFC). Three mixed designs with different fiber percentages (0%, 0.5%, and 1%) were considered for evaluation of the effects of these bacteria and polypropylene fiber on the mechanical properties and durability of LWC, which contained Leca aggregate. The experimental results indicated that the simultaneous addition of bacteria and fiber was effective and improved compressive, tensile, and flexural strength. It also reduced concrete water absorption and permeability in the specimens. In specimens with B. licheniformis and 1% fiber, a maximum increase of approximately 32.65% was observed in tensile strength and a 28.39% decrease was observed in water absorption with respect to the control specimens. A comparison of the bacterial specimens revealed that B. licheniformis and B. megateterium performed better in the induction of calcium carbonate precipitation and distribution of fiber in the concrete matrix than S. pasteurii and S. ureae to reduce the balling phenomenon. In addition, SEM-EDX and XRD analyses were conducted to verify the formation of calcium carbonate in the concrete matrix and characterize the crystalline phases of the calcite.

УДОБОУКЛАДЫВАЕМЫЙ БЕТОН БЫСТРОГО ТВЕРДЕНИЯ ДЛЯ ПРОИЗВОДСТВА БУРОНАБИВНЫХ СВАЙ

The article presents the results of the effect of a complex additive on improving the physical and mechanical characteristics of the material. The evaluation of the physical and mechanical characteristics of concrete was made for four types of concrete. The main parameters were: setting time, compressive and flexural strength, water absorption. In the presented work the authors used a complex additive containing in its composition alkali (caustic soda), post-alcoholic bard (alcohol production waste) and hardening regulator (gypsum) in different ratios. It is shown that the combined use in the composition of a complex additive, which has well-compatible mechanisms of their influence on the processes of hydration, setting and hardening of the cement mass, mutually complements and enhances the effect of each ingredient of the additive. Increasing the concentration of the complex additive in the cement mixture up to 7% of the cement mass not only affects the process of cement mortar liquefaction, shortening the time of setting and hardening of the cement mass, but also increases the compressive strength of the cement in all periods of hardening. The analysis suggests that the complex additive provides a reduction in water absorption of concrete. It has been revealed that concrete with the studied complex additive has high physical and mechanical properties. The optimum dosages of the considered additive have been found and used in the present work.

Partial Replacement of Cement by Waste Paper Pulp Ash and Its Effect on Concrete Properties

An investigation was conducted to study the viability of using waste paper pulp ash as an alternative material applied as a partial replacement of cement in the manufacturing of concrete and its effect on the properties of concrete, and also, the cost and environmental advantage of using waste paper were examined. Four concrete mixes with 0%, 5%, 10%, and 15% waste paper pulp ash replacement of OPC and PPC for 25 MPa concrete were prepared. Based on the results obtained from the research, the highest compressive strength obtained at all test ages, i.e., 3, 7, and 28 days, were, 24.36, 28.35, and 36.83 MPa, respectively, with 5% replacement of waste paper pulp ash for OPC, and for PPC, all percentage replacements showed reduction in compressive strength than the control mix. The water absorption of concrete was increased with increasing the percentage of waste paper pulp ash than control concrete. The control concrete clearly has the lowest resistance to 2% sulfuric acid solution compared to blended concrete of OPC‐WPPA and PPC‐WPPA. The cost comparison indicates that the incorporation of waste paper pulp ash decreases the cost of concrete and WPPA and saves raw materials used in cement and concrete production.