Cementitious Material In Concrete Research Articles

Technical, economic, and environmental feasibility of rice hull ash from electricity generation as a mineral additive to concrete

A circular economy based on symbiotic relationships among sectors, where the waste from one is resource to another, holds promise for cost-effective and sustainable production. This research explores such a model for the agriculture, energy, and construction sectors in California. Here, we develop new an understanding for the synergistic utilization mechanisms for rice hull, a byproduct from rice production, as a feedstock for electricity generation and rice hull ash (RHA) used as a supplementary cementitious material in concrete. A suite of methods including experimental analysis, techno-economic analysis (TEA), and life-cycle assessment (LCA) were applied to estimate the cost and environmental performance of the system. TEA results showed that the electricity price required for break even on expenses without selling RHA is $0.07/kWh, lower than the market price. As such, RHA may be available at little to no cost to concrete producers. Our experimental results showed the viability of RHA to be used as a supplementary cementitious material, meaning it can replace a portion of the cement used in concrete. LCA results showed that replacing 15% of cement with RHA in concrete can reduce carbon dioxide equivalent (CO2e) emissions by 15% while still meeting material performance targets. While the substitution rate of RHA for cement may be modest, RHA generated from California alone could mitigate 0.2% of total CO2e from the entire cement production sector in the United States and 1% in California.

A COMPREHENSIVE REVIEW OF THE USE OF NEUTRAL CARBON AND BIO-OIL WASTES ON WARM MIX ASPHALT CONCRETE

Waste materials can be used to produce cement concrete, asphalt concrete, block concrete, and other construction materials. This has been known for more than 30 years in the field of civil engineering. To allay ecological concerns, several nations are currently researching the reprocessing of neutral carbon and bio-oil wastes (NC&BoWs). These wastes are sustainable, but because of their large volume of landfill disposal, which has detrimental effects on the ecosystem and its inhabitants, they are starting to become quite worried for the ecosystem. Therefore, this study provides a comprehensive review of the use of NC&BoWs on warm mix asphalt (WMA) concrete to lessen our worries about the environment. Numerous investigations have been conducted to enhance various WMA technologies. These three technologies such as foaming, chemical, and organic enhance the structural behavior of WMA concrete and lower the viscosity of the asphalt binder. A bibliometric analysis shows that only 26 out of the 168 articles related to this study were published by Scopus between 2012 and 2023. Full-length articles accounted for 100.0% of Scopus publications, and it seems that not a single review article was accepted and published by Scopus. Based on the subject area, the fields of engineering, materials sciences, and physics and astronomy published 50.0%, 43.5%, and 6.5% of the Scopus articles, respectively. Consequently, the findings suggested that further reviews are necessary to verify NC&BoWs' ongoing efficacy in WMA concrete

Process optimization of acq-polyacrylate modified bamboo aggregate and durability analysis of all-bamboo aggregate concrete

All-Bamboo Aggregate Concrete (BAC) is a type of cement concrete material where all coarse aggregates are made of bamboo aggregate, a plant material that requires necessary measures to avoid or slow down its degradation in alkaline and natural environments. This paper enhances the durability of BAC materials through the treatment of bamboo aggregate with ACQ-polyacrylate (AP method). Initially, the study explores the impact of polyacrylate dilution concentration on the compressive strength and coating thickness of BAC, and based on a reasonable modification process, conducts freeze-thaw cycles, salt solution immersion, accelerated wet-dry aging, and long-term natural environment tests to assess the durability of BAC materials. The results show that a polyacrylate solution with a dilution ratio of 1:5 can form a coating thickness of 23.8μm, performing better in various durability evaluations. After 25 freeze-thaw cycles, the BAC material's loss rate of compressive strength is lower than that of Ordinary Concrete (OC). Compared with OC, BAC materials are more susceptible to salt damage after salt solution immersion. The compressive strength loss rate under 180 days of natural environment exposure is comparable to that in 10 cycles of accelerated wet-dry aging, 28 days of salt solution immersion, and 10–15 freeze-thaw cycle tests, recommending the use of freeze-thaw cycle tests for evaluating the durability of BAC materials from an experimental efficiency perspective. By exploring the durability of BAC materials, this paper provides an innovative solution in the field of construction materials, promoting the transition of the construction industry towards sustainable development. It emphasizes the feasibility and effectiveness of improving the performance of bamboo-based materials through surface treatment technology, offering a valid reference for developing more environmentally friendly and high-performance new materials in the future.

Gelatin‐based air‐entraining agents for ordinary portland cement: Chelate Ca2+ and reduce surface tension

AbstractIntroducing uniform, stable, and small pores by adding air‐entraining agents (AEAs) is an effective strategy for improving the freeze–thaw resistance and workability of cement concrete materials. In this study, the gelatin with hydrophobic and hydrophilic functional groups was used as an AEA for cement concrete materials and systematically studied its effect on the performance of cement mortar specimens. The results showed that gelatin has a surfactant‐like function and can effectively reduce the surface tension of the gas–liquid interface. In an alkaline environment, Ca2+ ions in cement pore solution chelate with carboxylate ions formed by carboxyl ionization, further enhancing the performance of gelatin‐based AEAs. Thanks to the reduction in surface activity and carboxyl ionization, introducing gelatin increased the porosity of cement mortar specimens from 0.53% to 2.69%. Furthermore, introducing an appropriate amount (>0.1 wt%) of gelatin does not significantly impact the workability or mechanical properties of cement mortar. Based on these characteristics, gelatin has potential as an AEA for cement concrete materials.

Reliability Analysis of Compressive Fatigue Life of Cement Concrete under Temperature Differential Cycling

Cement concrete, as an extensively used engineering material, is omnipresent in various infrastructure projects such as bridges and roads. However, these structures often need to operate for extended periods under varying and harsh environmental conditions, facing not only complex vehicular loads but also the effects of temperature differential cycling. Consequently, understanding how temperature differential cycling impacts the compressive fatigue life of cement concrete has become a pivotal research topic. In this study, through a comprehensive experimental design, the fatigue life of cement concrete under typical temperature difference conditions (20–60°C) and different number of temperature differential cycling (60, 120, 180, 240, 300) was tested at three stress levels (0.70, 0.75, 0.85). Statistical analysis was conducted to obtain the Weibull distribution parameters of the compressive fatigue life of cement concrete. The Pf–S–N relationship of concrete considering reliability was analyzed, and a fatigue life prediction model under different reliability probabilities was established. The results show that the fatigue life of concrete subjected to temperature differential cycling follows a two-parameter Weibull distribution well. From the Pf–N curve, it can be seen that, regardless of the stress level, the calculated fatigue life under the same reliability probability decreases with the increase of temperature differential cycling times. At a 95% reliability probability, the decrease can reach 77.5%–87.5%. Based on the exponential function, a concrete fatigue life prediction model based on different reliability levels was established. Using this model, the S–lgN curve was plotted, and it was found that, regardless of the temperature differential cycling, an increase in reliability probability could lead to a 7.3%–14.4% reduction in logarithmic fatigue life (lgN). Additionally, this study also defined a fatigue life safety factor related to the number of temperature differential cycling and reliability probability, aiming to provide a theoretical basis for the design of cement concrete materials under the coupled environment of temperature differential cycling and fatigue loading.

Mechanical properties and microstructure of waterborne polyurethane-modified cement composites as concrete repair mortar

With the increase in service life, the durability of a large number of concrete structures deteriorates year by year under the influence of the external environment, requiring urgent repair and reinforcement. Ordinary cement concrete materials have disadvantages such as high brittleness, low tensile strength, poor bonding ability, and insufficient durability, making it difficult to meet the repair needs of high-quality building structures. Therefore, self-synthesized anion WPU was used to study its effect on the mechanical properties of cement-based repair mortar. The research found that waterborne polyurethane (WPU)-modified cementitious composite repair materials exhibit better bonding strength with old concrete substrates compared to traditional cement-based materials. Additionally, the incorporation of WPU significantly reduces the brittleness of the repair material, ensuring enhanced efficiency in the repair process. However, according to the hydration heat test results, the addition of WPU delays the hydration process of the composite repair materials. In addition, the addition of WPU enhances the flexibility and bonding ability of the materials, with flexural strength and tensile strength at the age of 28 days reaching 13 MPa and 6 MPa, respectively. Through stress‒strain curve analysis, it was found that the maximum strain amplification of WPU cement mortar can reach 134 %. Combined with SEM testing, it was observed that cured WPU films were present in specimens aged 28 days with P/C ratios of 10 % and 15 %. WPU and cement hydration products permeate each other, forming a three-dimensional polymer network structure, improving the pore structure, and fully exerting the flexibility of WPU. This also validates the experimental results of increased ultimate tensile strain. WPU cement-based composite repair materials have higher bonding strength at a high P/C ratio (15 %), and WPU alone, used as an interface agent for pretreating the interface of old concrete, can improve the interface bonding strength, up to twice that of the group without the surface agent.

Effect of Marble Dust Powder on the Properties of Fresh and Hard Concrete

The goal is to investigate the potential for employing byproducts from various industrial processes in the creation of ground-breaking mortar and concrete. The dust produced during the marble-cutting operation is put to good use. Different percentages of this garbage were recommended to be used in conjunction with or in place of cement in the making of concrete. The research looked into the possibility of using marble dust, which is produced during the shaping of marble blocks, as a cementitious material in concrete. In areas where they are readily available and can reduce construction costs, the study found that dust from marble slabs could be employed as a cementitious material in concrete mixtures. The discarded marble dust is mixed with cement in proportions of 5, 10, 15, and 20% of the standard concrete mix. Both the fresh and hardened characteristics of the produced combinations were investigated. Compressive and tensile strengths were measured after being cured for varying periods of time, both when marble dust was used as a partial replacement and when it was not.

SHOTCRETES AND MORTARS FOR 3D PRINTERS USING CHINESE INDUSTRIAL WASTE

Currently, ordinary Portland cement is the main cementing material for shotcrete in tunnels in my country. Part of the use of single-doped silica fume or fly ash, however, there are few cementitious materials that use double-doped or multi-doped mineral admixtures. Due to the single composition of the cementitious material, poor gradation, and low quality, the concrete has poor compactness, insufficient viscosity, and large rebound. The use of "multiple" mineral admixtures can better solve the problem of high rebound rate of shotcrete in tunnels. Among them, mineral admixtures include mineral powder, fly ash, silica fume and limestone powder. The cementitious material in concrete can be single-mixed, double-mixed or multi-mixed with mineral admixtures. In this way, the heat of hydration when the concrete sets and hardens can be reduced, reduce the cracking of concrete, improve the compactness and viscosity of concrete and reduce the rebound rate of concrete.
 The aim of research: the overall idea and technical measures to solve the high rebound rate of shotcrete or 3D printer mix and the high amount of cementitious materials using Chinese industrial waste.
 Scientific novelty of research: optimal compositions using Chinese industrial waste for wet shotcrete, optimal compositions using Chinese industrial waste for 3D construction printers, basic properties of wet shotcrete composites with using Chinese industrial waste, basic properties of 3D construction printer composites with using Chinese industrial waste.

Sugarcane Bagasse-Derived Carbon for Partial Replacement of Cementitious Material in Concrete

Sugarcane Bagasse-Derived Carbon for Partial Replacement of Cementitious Material in Concrete

Exploring the resilience of supplementary cementitious materials-based concrete to elevated temperatures via modern computing techniques

Researchers are focused on the production of sustainable materials in order to reduce the negative environmental impact of conventional concrete. Utilizing industrial by-products as alternative cementitious materials in concrete is an appropriate strategy for promoting sustainability in construction. This research employed supervised machine learning techniques, including gradient boosting (GB), random forest (RF), and extreme gradient boosting (X-GB), in order to predict the compressive strength of sustainable concrete when exposed to high temperatures. SHapley Additive exPlanation (SHAP) analysis provided input component relevance. The comparison of these methodologies indicated that X-GB performed remarkably well and had a superior R2 value of 0.94 when compared to GB and RF. The results were further supported by a Taylor diagram, which demonstrated that the X-GB model best fitted the data, surpassing both the GB and RF models. This study's findings demonstrated the potential of machine learning, and more particularly X-GB, for making accurate predictions of compressive strength in high-temperature concrete applications. The results of SHAP analysis may be useful for selecting the proportions of raw materials in the mix design to achieve the desired properties.

Experimental investigation and modelling of the mechanical properties of palm oil fuel ash concrete using Scheffe’s method

This study explores the enhancement of mechanical properties in concrete blended with palm oil fuel ash (POFA) through Scheffe's optimization. The utilization of POFA as supplementary cementitious material in concrete has gained attention for its potential environmental benefits. Utilizing a (5,2) simplex-lattice design, a systematic approach is employed for optimizing mixture proportions based on response parameters. The laboratory tests to evaluate concrete's mechanical behavior were conducted using the computed mixture ratios from the design experimental points after 28 days of hydration. The results showed maximum flexural strength at 8.84 N/mm2 and compressive strength at 31.16 N/mm2, achieved with a mix of 0.65:0.54:2.3:3.96:0.35 for cement, water, coarse aggregate, fine aggregate, and POFA. Additionally, maximum splitting tensile strength reached 8.84 N/mm2 with a mix of 0.62:0.55:2.09:3.86:0.38 for the same components. Conversely, the minimum flexural, splitting tensile and compressive strength within the experimental factor space was 4.25, 2.08 and 19.82 N/mm2 respectively. The results obtained indicated a satisfactory mechanical strength performance at POFA replacement of 35 percent in the concrete mixture. The developed mathematical model was statistically validated using analysis of variance (ANOVA) at a 95% confidence interval which showed satisfactory prediction performance. The findings from this study provide valuable insights into optimizing POFA-blended concrete for enhanced mechanical performance, offering potential sustainable solutions for the construction industry.

ВНУСТРІШНЬОСТРУКТУРНІ ТЕРМОНАПРУЖЕННЯ В АСФАЛЬТОБЕТОННИХ І ЦЕМЕНТОБЕТОННИХ МАТЕРІАЛАХ, ПІДСИЛЕНИХ ФІБЕРГЛАСОВОЮ, ФІБЕРКАРБОНОВОЮ, ФІБЕРБАЗАЛЬТОВОЮ ТА ФІБЕРАРАМІДНОЮ АРМАТУРОЮ

By the methods of mathematical modeling, the internal structural thermomechanical effects that are blamed on asphalt concrete and cement concrete materials, reinforced with the fiberglass, fibercarbon, fiberbasalt and fiberara-mide strands, are investigated under conditions of change the temperature of the system. The analysis of the thermome-chanical incompatibility of the phases of the composites with the aim of establishing its influence on the values of the internal structural thermal stresses, which are attributable to these changes, is performed. It is shown that for the as-phalt concrete material the incompatibility is small and so the system internal structural thermal stresses are also small and do not exceed the values of the limit strength of the fractions of the composite material. For composites with a cement concrete matrix, the thermomechanical incompatibility of their fractions is essential and for this reason the ther-mal stresses, which are due to the temperature change, significantly exceed the values of the limit strength of the cement concrete. The established features may be used during the design of reinforced road pavements and cement concrete structures, which work under conditions of changing temperatures. Keywords: composite materials, reinforced concrete, epoxy coating, corrosion damage, thermomechanical incompati-bility, thermal stress.

Effect of high temperature modification on the highly adsorptive manufactured sand dust concrete

The production process of manufactured sand generates a large amount of dust, which poses a serious threat to the environment. In this study, we selected highly adsorptive manufactured sand dust of three lithologies (diabase, tuff, and basalt) for high temperature calcination. We evaluated its mechanical properties and microstructures after high temperature modification using various characterization methods to investigate its feasibility as a supplementary cementitious material (SCM). A comparative analysis of the manufactured sand dust before and after modification was conducted using thermogravimetric-differential scanning calorimetry (TG-DSC), laser particle size analysis, X-ray diffraction (XRD) and X-ray fluorescence spectrometry (XRF) techniques, the results showed that high temperature modification can reduce the crystallinity of the mineral impurities in the manufactured sand dust. Furthermore, the average particle size of artificial sand dust from all three lithologies (diabase, tuff, and basalt) was reduced. However, the flowability of the mortars increased by 12.1%, 7.4%, and 6.4% respectively. The 28-day volcanic ash activity index reached 63%, 61%, and 60% respectively. In addition, we used the modified manufactured sand dust as a supplementary cementitious material in concrete. It was found that when 30% of cement was replaced with a 1:2 mixture of manufactured sand dust and fly ash, the compressive strength at 90 days reached a maximum of 90.6 MPa. These results demonstrate that the modified manufactured sand dust has certain economic benefits and can be used to partially replace cement in concrete. This provides a basis for the development and application of highly adsorptive manufactured sand in the long term.

Thermomechanical Aspects of Frost Resistance of Cement and Asphalt Concrete Materials

Thermomechanical Aspects of Frost Resistance of Cement and Asphalt Concrete Materials

Performance of cement-based materials incorporating ultra-fine copper slag

The application of copper slag (CS) as a supplementary cementitious material in concrete is unsatisfactory due to the fact that CS is mainly composed of fayalite. The dissolution kinetics of fayalite determines the pozzolanic activity of CS. How to improve the dissolution of fayalite is a challenge for CS resource utilization. To address this issue, ultra-fine CS with different fineness was fabricated by wet-grinding method for the first time in this work and the performance of cement-based materials incorporating ultra-fine CS was assessed. Results revealed that an increase in CS fineness significantly promoted the decomposition of fayalite to improve the mechanical strength of mortars. The 7 d and 28 d strength activity index of ultra-fine CS can reach 106% and 102%, respectively, which has seldom been reported in the literature. Although ultra-fine CS can significantly accelerate the hydration process at the very beginning of reaction to form more hydrates, the early-age pozzolanic activity was still not ideal. The prepared ultra-fine CS exhibited good later-age pozzolanic activity, which can consume more portlandite and generate more hydrates, resulting in a denser microstructure. These results indicated that ultra-fine CS can be used as a high-quality alternative cementitious material to improve the greenness of cement and concrete products.

Development of Ultra High-Performance Fiber reinforced concrete barge for 5 MW wind turbine

Floating wind turbines are gaining more popularity today as one of the effective green energy harvesting systems. In the effort to reduce the cost of construction for floating wind turbines, concrete support structures and concrete barge have been developed. However, due to the concrete low tensile strength and susceptibility to chemical action and freezing temperatures, the concrete barges are designed with very large sections resulting in high energy consumption, high volume of construction materials, weightier structure and more heavy equipment for fabrication and installation. Therefore, in order to overcome these challenges, in this study Ultra High-Performance Fiber Reinforced Concrete (UHPFRC) is proposed for use in casting a barge for a floating offshore wind turbine and compared to a reinforced cement concrete (RCC) barge. The experimental tests conducted on the UHPFRC and RCC barge small sized prototypes, showed less heel on the RCC barge compared to the UHPFRC barge. However, the RCC barge experienced severe green water load which could cause it to capsize. The hydrodynamic analysis results from the finite element analysis showed less pitch motions in the UHPFRC barge in 7 out of the 12 DLCs considered. The roll motions were less than 50 in both barges with insignificant difference between them, while in heave motions, the UHPFRC barge experienced 10% to 20% less motions than the RCC barge in all 12 DLCs. In the structural analysis, the maximum deformation of the UHPFRC barge was 14 mm, which is 129% higher than the deformation of the RCC barge. In overall, the UHPFRC barge proved to be more effective in achieving better hydrodynamic motions for the barge floater in comparison to the RCC barge and can be considered as alternative to the conventional reinforced cement concrete material.

Potential of ladle furnace slag as supplementary cementitious material in concrete

This research investigated the suitability of a locally available ladle furnace slag (LFS) as a supplementary cementitious material (SCM) to partially replace cement in concrete. The engineering properties of the LFS blended concrete were evaluated through an extensive experimental program. The SCM was used as (i) raw slag and (ii) sieved (finer than 75 µm) slag to use to produce different strength class concrete, viz., C35 and C40. Mechanical strengths and non-destructive tests were conducted for concrete with 5%, 10%, 15%, 20%, 25%, and 50% LFS replacement by weight of cement for various curing duration. Besides, indirect durability tests such as sorptivity and nitrogen gas permeability tests on LFS blended concretes were performed. Uniaxial compressive strength (UCS) for lower-grade concrete at 5% and 10% LFS levels are always higher relative to the control sample, regardless of the material type and curing period. The ultrasonic pulse velocity (UPV) test on concrete suggests that pulse velocity has a pattern similar to that of the UCS. Nitrogen gas permeability varies by LFS level, temperature, and material fineness. Capillary absorption indicates an evident general trend of increased water absorption with exposure/absorption time and LFS level. These properties for higher-grade concrete are reasonably similar to that of lower-grade concrete, however, the finer material shows better performance in this case.

Study on the effect of plant extracts as low carbon green admixtures on the performance of cement mortar

The pollution of the environment by chemical admixtures for cement and concrete and the carbon emission in the production of cement and other concrete raw materials have attracted increasing attention from scholars. In order to improve the physical and mechanical properties of cement, eliminate pollution and reduce carbon emission, this paper uses natural plant extracts (cactus sativus extract and mulberry leaf extract) as admixtures to make cement mortar. The consistency, water absorption, compressive strength, flexural strength, chloride ion penetration resistance and microstructure of the mortar were tested and analyzed, the effects of different admixtures of natural plant extracts on the physical and mechanical properties of cement mortar were investigated. The results show that the consistency of the cement mortar was increasing with the increase of the admixture of cactus sativus extract and mulberry leaf extract; the admixture of cactus sativus extract and mulberry leaf extract did not change the hydration reaction and hydration products. When the admixture amount was lower, the extracts could promote the hydration reaction, improve the internal crystal morphology and generate more C-S-H, thus improving the physical and mechanical properties of cement mortar. The physical and mechanical properties of the cement mortar were optimized when the amount of mulberry leaf extract was 0.15% of the cement mass, and the overall performance was improved more compared with that of cactus extract. With the increase of amount of admixture, the viscosity of the system increases due to plant extracts, and the air bubbles formed during mortar mixing cannot be discharged and form micro-pores inside, resulting in the reduction of physical and mechanical properties. As a low carbon green admixture, plant extract is worthy of further research and promotion.

Statistical analysis on mechanical behaviour of ternary blended high strength concrete

The growing demand for high strength concrete [HSC] in the construction industry increases the usage of cement, resulting in environmental issues. Recent studies are showing that the utilization of cementitious materials in concrete can effectively reduce the volume of cement. In the present study, ternary blended combinations were prepared using cement, silica fume, and fly ash to attain the HSC. Here, cement was partially replaced by silica fume [2.5, 5, 7.5, and 10%] and fly ash [5, 10, and 15%], respectively. Mini slump cone test was conducted to identify the compatibility of cement paste with polycarboxylate ether [PCE] based superplasticizer. The packing density of aggregates was calculated to reduce the voids and improve the particle distribution in HSC. An experimental investigation was carried out, and the ultimate compressive strength was obtained as 71.55 MPa at 28 days of curing. Multi linear regression analysis was conducted to simulate the mix design for aiding the prediction of compressive strength of the HSC.

Ensemble Machine-Learning-Based Prediction Models for the Compressive Strength of Recycled Powder Mortar.

Recycled powder (RP) serves as a potential and prospective substitute for cementitious materials in concrete. The compressive strength of RP mortar is a pivotal factor affecting the mechanical properties of RP concrete. The application of machine learning (ML) approaches in the engineering problems, particularly for predicting the mechanical properties of construction materials, leads to high prediction accuracy and low experimental costs. In this study, 204 groups of RP mortar compression experimental data are collected from the literature to establish a dataset for ML, including 163 groups in the training set and 41 groups in the test set. Four ensemble ML models, namely eXtreme Gradient-Boosting (XGBoost), Random Forest (RF), Light Gradient-Boosting Machine (LightGBM) and Adaptive Boosting (AdaBoost), were selected to predict the compressive strength of RP mortar. The comparative results demonstrate that XGBoost has the highest prediction accuracy when the a10-index, MAE, RMSE and R2 of the training set are 0.926, 1.596, 2.155 and 0.950 and the a10-index, MAE, RMSE and R2 of the test set are 0.659, 3.182, 4.285 and 0.842, respectively. SHapley Additive exPlanation (SHAP) is adopted to interpret the prediction process of XGBoost and explain the influence of influencing factors on the compressive strength of RP mortar. According to the importance of influencing factors, the order is the mass replacement rate of RP, the size of RP, the kind of RP and the water binder ratio of RP. The compressive strength of RP mortar decreases with the increase in the RP mass replacement rate. The compressive strength of RBP mortar is slightly higher than that of RCP mortar. Machine learning technologies will benefit the construction industry by facilitating the rapid and cost-effective evaluation of RP material properties.