Portland Pozzolana Cement Research Articles

Arriving the optimum retarder dosage level of sugar on the setting time, compressive strength, and microstructure property of Portland pozzolana cement

AbstractCement and concrete are the most crucial and dominating engineering materials in the construction sector. Cement serves as an excellent binder for concrete and when it is treated under unusual conditions either to satisfy accelerating or retarding requirements by the construction industries, admixtures role comes into the effect. The construction industry has been searching for retarding admixtures and the optimal dosage level, particularly for ready mix concrete applications. Generally the retarding admixtures such as organic retarders (lignosulphonates, hydroxycarboxylic acids and their salts, phosphonates, sugars) or inorganic retarders (phosphonates, borates) were generally used to reduce the speed of the reaction between cement and water by altering the growth of the hydration products and/or limiting the rate of water penetration to the cement particles. The research was still in its infancy stage in terms of determining not just the appropriate dosage amount, but also the ideal retarder materials for the aforementioned uses. In considering this industrial need, an attempt was made on utilizing the usage of sugar in the concrete to study the retarding effect without affecting the strength properties of cement. The sugars usage levels were at 5, 10, 15, and 20% of the usage of cement to investigate consistency, setting time, compressive strength and micro structure properties at the curing age of 7, 14 and 28 days on the mortar specimens. The conclusions of the study reported that setting time was extended with increase of the dosage levels of sugar. However in considering the strength property, less than 5% of sugar dosage level can be better for the application as retarding agent in the industry applications.

Analysis of Cement properties using Hyperspectral Remote Sensing methods

Abstract. Understanding building material properties can play a key role in analyzing the health of structural elements in buildings. However, the field and laboratory tests can be laborious, time-consuming, and cost-intensive. Generally, the standard tests employed for characterizing the material properties are destructive in nature, but in the recent past, non-destructive testing (NDT) has given us the ease of understanding the material properties. Hyperspectral remote sensing technology has been exploited as one of the NDT methods for assessing the properties of building components. This study aims to investigate the quality information about cement using the hyperspectral remote sensing method and correlate it with the results of traditional quality testing methods. The materials used in the experiments included Ordinary Portland Cement (OPC), Portland Pozzolana Cement (PPC), and White Portland Cement (WPC). The cement samples were studied and experimented with for the identification of their types, and their temporal variability and changes in their spectral properties on which the strength of the samples depended were further checked. The study concluded that for OPC, PPC, and WPC, the absorption range is 1970 nm to 2020 nm, which is mainly due to the presence of different chemical compounds in cement. Also, the spectral reflectance decreases with time, and it can be concluded that in the present work, the strength of cement decreases with the decrease in spectral reflectance. Hence, Cement properties can be found using hyperspectral remote sensing data.

An investigation of the rheological parameters of slurry composed of ordinary Portland cement, Portland pozzolana cement and Portland slag cement

ABSTRACT This paper compares the rheological parameters of ordinary Portland cement of grade 43 (OPC 43), ordinary Portland cement of grade 53 (OPC 53), Portland pozzolana cement (PPC) and Portland Slag Cement (PSC) to study the thixotropic built. Five slurries with increasing water/cement (w/c) ratios from 0.52 to 0.6 were prepared and examined at resting times of 1 minute, 5 minutes and 10 minutes. Static shear stress (τs), dynamic shear stress (τd) and thixotropic index (β) were studied to analyze the thixotropic built of the slurries. The rheological parameters increase for all the mixes with decreasing w/c ratios and increasing resting times. However, for a w/c ratio greater than 0.60, all the mixes lose their plastic viscosity and the rheological parameters approach non-significant values. The τs and τd values for PPC and PSC pastes are higher than those of the OPC pastes because of the increase in cement fineness and increased rate of structuration and hydration. OPC 53 paste shows high β because of the large extent of reversible thixotropic built. The τs values obtained from the viscometrical tests were then compared the mini slump test values. Results show that the rheological parameters are more consistent than the flow values of the mini slump cone test.

VARIATION OF TANGKILING AGGREGATE SIZE AND ITS IMPACT ON COMPRESSIVE STRENGTH AND ELASTICITY MODULUS OF CONCRETE

The use of coarse aggregate significantly influences the mechanical properties and overall quality of concrete. This study investigates the impact of different coarse aggregate sizes (10 mm, 20 mm, and 40 mm) on the compressive strength and elastic modulus of concrete at 28 days. The research was conducted as part of a thesis in the Building Engineering Education Program, Department of Vocational Technology Education, Faculty of Teacher Training and Education, Universitas Palangka Raya. The primary objective was to determine the compressive strength and elastic modulus values for concrete mixes using varying coarse aggregate sizes. The concrete mixtures incorporated different coarse aggregate sizes along with fine aggregate, water, and Portland Pozzolana Cement (PPC) type I from Gresik. The mix design followed the guidelines outlined in SNI 03-2843-2000 for normal concrete mixtures. Testing was performed on cylindrical specimens measuring 15 cm x 30 cm. Each aggregate size variation (10 mm, 20 mm, and 40 mm) was tested using 10 samples, and the tests were conducted at 28 days in the Laboratory of Building Engineering Education, Faculty of Teacher Training and Education, Universitas Palangka Raya. The average compressive strength at 28 days for the coarse aggregate variations of 10 mm, 20 mm, and 40 mm were 29.15 MPa, 28.60 MPa, and 28.50 MPa, respectively. The average elastic modulus at 28 days for the same variations were 3033 MPa, 3856 MPa, and 3950 MPa.

Hydration behavior of Portland pozzolana cement in the presence of nano-silica

Hydration behavior of Portland pozzolana cement in the presence of nano-silica

Characteristic evaluation and environmental validation of self-compacting concrete containing sandstone slurry waste for sustainable usage.

This study aims to understand the impact of concrete ingredients on the environment. To analyze the effect of, three significant indexes have been taken into consideration, which are embodied carbon dioxide index (e-CO2), embodied energy consumption (e-energy), and embodied resource consumption (e-resource) index. The life cycle assessment (LCA) methodology has considered veto comprehending the probable application of sandstone waste in the form of a slurry (Sslurry) and powder (Spowder) for the development of self-compacting concrete (SCC). This study can be proven beneficial to evaluate the potential adverse effects from environmental and energy perspectives. One reference mix and eighteen design mixes of SCC have been designed and developed to perform an experimental program. An environmental impact comparison of the "hybrid" SCC was performed using the OpenLCA life cycle analysis software with Ecoinvent LCIA methods. The outcomes of this experimental program reveal that the partial replacement of pozzolana Portland cement (PPC) with Sslurry can reduce e-CO2 emission along with the e-energy and e-resource parameters. When Spowder was used as the partial substitution of fine aggregate (FA), only the e-resource index decreased, and e-CO2 and e-energy increased. Minimalist impact on the environment has been noticed when SCC is prepared with Sslurry and Spowder. A detailed LCA analysis study justifies the utilization of Sslurry and Spowder in SCC, which exhibits encouraging results concerning strength and quality. Hence, it was observed that Sslurry and Spowder in developing green and sustainable SCC with moderate strength characteristics are beneficial from an environmental impact perspective.

Evaluation of sulfuric acid effect on bending strength of steel used in concrete reinforcement in sanitation structures

Most sanitation structures in the world are constructed using concrete which is reinforced by the steel, this type of concrete is called Reinforced Cement Concrete (RCC). The RCC structure is believed to be relatively resistant to corrosion which the sanitation structures are prone to due to the aggressive environment in which they are subjected to. This belief has been compromised since the reinforced concrete used in the sanitation structures such as the concrete sewer pipes has become susceptible to Microbiologically Induced Deterioration (MID). This MID leads to degradation and compromised strength and service life of the RCC. In the reinforced concrete structure, the backbone of this structure is the reinforcing steel which when its strength is compromised by the MID, the whole structure is compromised. The present research therefore aimed at evaluating the effects of sulfuric acid, resulting from the MID process, on the bending strength of steel metal used for reinforcing concrete in sanitation structures. Reinforced concrete specimens were developed using different types of cement and different concrete cover. The three different types of cement were, Ordinary Portland Cement (OPC), Portland Pozzolana Cement (PPC) and Limestone Calcined Clay Cement (LC3), while concrete covers of 15mm and 25mm were applied. They were then subjected to a harsh environment (a sample of sewage) suitable for corrosion just like in their actual operational environment. To determine the effects of sulfuric acid resulting from MID on the steel metal, the steel metal was tested using a Universal Testing Machine (UTM). The bending strengths before and after being subjected to an aggressive environment were determined. The testing of the specimens was done at an interval of 14 days for a period of three (3) months. According to the results, for a concrete cover of 25mm, LC3 showed a minimum percentage reduction in strength compared to PPC and OPC. It had the lowest percentage reduction in strength after 84 days which was 5.25%, OPC 7.20%, and PPC 7.24%. In conclusion, there was a strength reduction for all specimens tested. LC3 showed good resistance to the effects of MID compared to PPC and OPC. In terms of concrete cover, 25mm showed good resistance to MID compared to 15mm concrete cover.

Evaluation of self-cleaning performance of TiO2-intermixed and TiO2-coated cement mortars under natural sunlight

Self-cleaning cementitious materials have gained significant attention due to urban environmental pollution. In this study, nano-TiO2 (NT) was first mixed with cement mortar. Second, NTs were coated on fresh cast mortars and on hardened surfaces. Photocatalytic efficiency was evaluated using Rhodamine B under natural sunlight with three types of cement: white Portland (WPC), ordinary Portland (OPC), and Portland pozzolana cement (PPC). Among them, PPC cement mortars exhibited superior photocatalytic performance compared to WPC and OPC even with lower dosages of NT. The order of photocatalytic efficiency was highest for the hard-coat followed by fresh-coat and then intermix sample. Furthermore, Rietveld analysis for crystal structure refinement was used, and crystallography analysis (VESTA software) confirmed the presence of specific atoms and bonds in the crystal structure of PPC with NT. Microstructural analysis using XRD, SEM, and EDAX revealed underlying structural changes and thus quantified the hydration products.

Effects of biogenic sulfuric acid on simulated concrete septic tanks

Concrete is the major construction material for infrastructure development. Concrete sewer septic tanks are Constructed using the conventional ordinary portland cement (OPC) and the Portland pozzolana cement (PPC). However, OPC based concrete sewer systems are susceptible to biological, mechanical, and chemical degradation. Degradation of the concrete septic leads to their failure hence imposing tremendous environmental problems. The aftermath is the emergence of sanitation-related diseases. The wastewater from failing septic systems leads to contamination of the groundwater or the surface water resulting in the pollution of drinking water. Therefore, the need to explore other possibilities and potential construction materials to achieve sustainable sanitation is inevitable. The use of Limestone Calcined Clay Cement (LC3) in the construction of degradation-resistant concrete sewer septic systems has not been well explored in Kenya. LC3 concrete is resistant to the deterioration effects of aggressive media such as acids, chlorides, and sulfates. This paper presents experimental performance and findings of LC3 in aggressive media vis a vis OPC. The LC3 was formulated by mixing clinker, Calcined clay, limestone, and gypsum at percentages of 50 %, 30 %, 15 %, and 5 % respectively. Compressive strength, Sorptivity, and weight loss during the wet and dry cycles for both LC3 and OPC were evaluated. Simulated concrete septic tanks made of LC3 and OPC were made by casting cubes at water cement ratio of 0.5 and cured in fresh water at ambient temperature for 28 days. These cubes were passed through a regime of W-D cycles in the 3% concentration of Biogenic sulfuric acid. It was observed that after 28 days of curing OPC cubes had slightly higher compressive strength than LC3. However LC3 concrete cubes are expected to have higher compressive strength than the OPC. Cubes curing time increases due to increased pozzolanic activity. Biogenic sulphuric acid attacks on hydrated cement products cause a decrease in compressive strength. The water absorption profile of LC3 cubes was lower as compared to OPC cubes. In conclusion, LC3 cubes had a high potential of resisting degradation as compared to OPC cubes. LC3 show more impressive performance, hence LC3 It’s a potential binder for use in the construction of sewer system.
 Keywords: Septic tank, Sorptivity, compressive strength, wet-dry cycles, biological, mechanical, and chemical degradation, sustainable sanitation, LC3.

3D printed concrete using Portland pozzolana cement - fly ash based

This project investigates the feasibility and properties of 3D printed concrete using Portland Pozzolana Cement (PPC). The increasing demand for construction materials, particularly ordinary Portland cement (OPC), has led to a surge in its usage. Consequently, Portland Pozzolana Cement (PPC) has gained popularity as an alternative due to its advantageous properties. PPC, characterized by its enhanced durability and sustainability, has become a preferred choice in the construction industry, offering versatility and reliability in various construction applications. The main focus of the project is economical printing of concrete structures through 3D printing technology. With sustainability and cost-effectiveness as paramount considerations, the study delves into refining the mix proportions ideal for 3D printing applications. By harnessing the potential of Portland Pozzolana Cement (PPC) with a 35% fly ash content, the aim is to strike a balance between structural integrity, workability, and affordability. It examines various key properties essential for successful 3D printing, such as extrudability, printability, flowability, buildability, setting time and thixotropic open time. Furthermore, the project examines the strength of 3D printed concrete mixes. Through testing and studying these properties, the research aims to contribute to the advancement of eco-friendly and efficient construction practices by using 3D printing and innovative cementitious materials. The findings from this study provide valuable insights to enhance the efficiency of 3D printing and the strength of printed concrete structures, including beams, walls, and other structural elements. By implementing these ideas, potential advancements in construction methodologies could be realized, facilitating more robust and cost-effective building practices. This research aims to contribute to the ongoing evolution of 3D printing technology in construction, ultimately fostering innovation and sustainability in the built environment.

Phosphorus adsorption from aqueous solutions using different types of cement: kinetics, isotherms, and mechanisms.

Exploring low-cost and high-performance phosphorus (P) adsorbents is key to controlling P contamination in water. This study evaluated the P adsorption performance of three types of cement: Ordinary Portland cement (OPC), Portland slag cement (PSC), and Portland pozzolana cement (PPC). Furthermore, SEM-EDS, XRD, XPS, and FTIR were employed to reveal the adsorption mechanism. The results showed that the pseudo-second-order model exhibited higher regression coefficients than the pseudo-first-order model, indicating that chemisorption dominated the adsorption process. The Langmuir equation fitted the P adsorption data well, with maximum P adsorption capacities of 245.8, 226.1, and 210.0 mg g-1 for OPC, PSC, and PPC at 25 °C, respectively. P adsorption capacities decreased gradually with increasing initial pH and reached their maximum values at pH 3. The anions of F-, CO32-, and SO42- negatively affected P adsorption due to the competitive adsorption with Ca2+. The results of XPS, XRD, and FTIR confirmed that Ca-P precipitates (i.e., hydroxyapatite) were the main removal mechanism. A real domestic sewage experiment showed that 0.6 g L-1 OPC effectively reduced the P concentration from 2.4 to below 0.2 mg L-1, with a dosage cost of 0.034 $ per ton. This study indicated that cement, as a low-cost and efficient P adsorbent, has great potential for application in removing P from acidic and neutral wastewater.

Assessment of the potential of rice husk ash (RHA) as a supplementary material in binary blended cement for road pavement applications

The current study explores the feasibility of using rice husk ash(RHA) as an additive in PPC (Portland Pozzolana Cement) concrete for rigid road pavement. The research investigates the impact of RHA on concrete’s strength parameters, specifically tensile, split tensile and compressive strengths. The conventional mix design method is applied for the controlled concrete, serving as baseline for designing mixes with varying percentage of RHA as a replacement for cement. The study examines five replacement levels: 5%, 7.5%, 10%, 12.5%, and 15%. Various curing durations are tested, including 3 days, 7 days, 28 days, and 56 days. The primary focus is to determine the optimal quantity of RHA as a cement replacement through experimental analysis. Key findings reveal that for compressive strength, the optimal replacement level is 10% RHA, while for flexural strength, the optimal replacement level is 5% RHA. These results underscore the potential of RHA to enhance concrete performance in road pavement applications when used judiciously as a partial substitute for cement.

Effect of Superplasticizer in Cement Type on Morphological Characteristics of Masonry Mortar

Cement plays a crucial role in mortar composition, and its particles exhibit a strong tendency to flocculate when mixed with water. This flocculation necessitates the addition of substantial water to improve the workability of mortar or concrete. However, this extra water does not contribute to the hydration reaction, potentially weakening the mechanical properties of the mortar. The introduction of superplasticizers has addressed this issue by reducing the water demand. Nevertheless, a common practice in construction is to use a standard dosage of superplasticizers for the same type of cement, even when sourced from different cement factories, which may affect material performance. This study investigated the influence of varying superplasticizer dosages on Portland pozzolana cement from different Ethiopian cement factories, examining the morphological characteristics of masonry mortar. Specifically, it evaluated the impact on cracks, porosity, and surface structure across different curing ages, as well as assessed the mortar’s physical and mechanical properties. Mortar samples prepared using cement from three factories, labeled A, B, and C, with constant cement‐to‐sand ratios of 1:3 and water‐to‐cement ratios of 0.5. Superplasticizer added in varying amounts 0%, 0.6%, 0.8%, and 1%. The morphological analysis conducted using a 3D optical surface profiler microscope at 1, 7, 21, and 28 days. Besides these standard physical and mechanical tests also performed on all samples. The results demonstrated that addition of superplasticizers significantly influenced the surface morphology of mortar samples. Mortars A and B exhibited denser structures with superplasticizer dosages 0.8% and 1%, respectively, whereas mortar C displayed a denser structure in its control state (without superplasticizer). The flexural and compressive strength tests also revealed notable differences. Sample A2 (0.8%) from group A, sample B3 (1%) from group B, and sample C0 (0%) from group C achieved the highest strength within their respective groups at 28 days. The findings suggest that it is essential to evaluate the specific properties of cement before applying a standardized superplasticizer dosage, as variations in cement production can significantly influence the performance of the mortar.

The effect of key parameters on the mechanical response of artificially cemented iron ore tailings for dry stacking purposes

Regulations prohibiting the construction of new tailings dams using the upstream method and requiring the closure of the existing ones have been recently introduced in Brazil. This scenario demands the sought for alternatives to manage both the previously disposed tailings as well as the upcoming generated mining residues. Fortunately, advances in dewatering technologies have enabled the tailings’ dried disposal in stacks having hundreds of meters rather than the traditional slurry deposition. Eventually, a cement material can be incorporated into the tailings before the stacking aiming to enhance the overall material’s performance, permitting the construction of higher and more inclined piles. In this regard,the present study evaluates the effect of key variables on the stiffness and strength of compacted iron ore tailings-cement blends. Specifically, the effect of the following variables was statistically evaluated through a full factorial design set: dry unit weight (17, 18, and 19 kN/m3), amount of cement (1, 3, and 5%), curing period (7, 28, and 90 days) and cement type (pozzolana Portland cement and high early strength Portland cement). The results have shown that all the main factors, and most of the second-order interactions, were significant in altering both the strength and stiffness of the studied mixtures, with a highlight to the amount of cement, curing time, and dry density. The type of cement, in turn, has exerted a marginal influence. As well, both responses could be successfully correlated to the adjusted porosity/cement index via power-type functions.

Predicting the Twenty-Eight Day Compressive Strength of OPC- and PPC-Prepared Concrete through Hybrid GA-XGB Model

This research set out to create a computational tool for predicting the 28-day compressive strength (CS) of concrete prepared from ordinary Portland cement (OPC) and Portland pozzolana cement (PPC) cement. 1,062 datasets of concrete were collected from laboratory experiments. From 1,062 datasets, 524 samples belonged to OPC and 538 samples belonged to PPC. eXtreme gradient boosting (XGBoost) algorithm optimized with genetic algorithm (GA) was utilized for developing an efficient model. The R value obtained for GA-XGBOPC and GA-XGBPPC models in training (TR) and testing (TS) dataset are almost ≥0.90. Mean absolute error (MAE) and root mean square error (RMSE) values obtained for the GA-XGBOPC model were 2.155 and 2.923, respectively. Similarly, the values for the GA-XGBPPC model were 1.815 and 2.888, respectively. The developed models were found to predict more than 90% of the observations within ±20% variations. The level-1 and level-2 validation results certify the GA-XGBOPC and GA-XGBPPC models’ generalizability. Ultimately, a user-friendly laborless and financially feasible computer software or tool was generated in Python for assistance to the field and design engineers in estimating the CS of concrete.

Durability assessment of concrete with natural and Linz Donawitz slag as coarse aggregates

Rapid growth of infrastructure has resulted in incessant consumption of natural aggregates in cement concrete leading to its depletion. Efforts have been made to utilize industrial by-products such as steel slag aggregates in concrete as partial replacement for natural aggregates. However, the utilization of Linz Donawitz (LD) slag aggregates in concrete is very limited compared to other slag aggregates. The limited utilization could be attributed to the expansive nature of LD slag aggregates, which may result in durability issues. In this study, the compressive strength and durability characteristics of concrete with 100% LD slag coarse aggregate are investigated considering three different cement types, including Ordinary Portland Cement (OPC), Portland Pozzolana Cement (PPC) and Portland Slag Cement (PSC) for all the mixtures. LD slag and control concrete were examined for durability by conducting water permeability, electrical resistivity, drying shrinkage, rapid chloride penetration (RCPT) and water absorption tests. X-Ray Diffraction (XRD) analysis along with the microstructural investigations using SEM-EDS was carried out to supplement durability results. The compressive strength results indicated that LD slag concrete depicted higher strength than control concrete and there was a steady increase in strength with curing duration. Interestingly, PSC concrete depicted higher rate of strength gain compared to other cements. Further, LD slag concrete depicted low permeability and water absorption compared to control concrete, where it can be anticipated lower freeze–thaw damage. RCPT results indicated lower penetration of chloride ions representing delayed corrosion of steel in LD slag concrete. Overall, LD slag concrete depicted enhanced durability than control concrete.

Effect of Magnesium Sulfate in Chloride Solution on Variation in Microstructure, Chloride Diffusion, and Chloride-Binding Behavior of Concrete

In this study, variation in microstructure, diffusion of chloride (Cl−) ions, and binding of chloride in concrete exposed to solutions containing MgSO4 (MS) in NaCl (NC) under the wetting-drying cycle are analyzed and reported. The results reveal that the amount of compounds such as ettringite (E), calcium hydroxide (CH), gypsum (G), calcite (CC), and calcium chloroaluminate (CCA) varies with the depth of concrete from the exposure face. Among exposure solutions, the amount of E was higher in NC + MS solutions compared with NC solutions and with increased MS content. The amount of CCA was higher in NC solutions compared with NC + MS solutions with an increase in NC content. The amount of CH was higher in concrete subjected to NC + MS solutions than to NC solutions and decreased with an increase in NC content. The amount of CCA was mostly higher in ordinary portland cement (OPC) with 20% fly ash concrete (O20FA-C) than in OPC concrete (OPC-C) followed by portland pozzolana cement (PPC) concrete (PPC-C). The amount of E was higher in O20FA-C than in PPC-C followed by OPC-C. Free chloride content (Cf) and apparent chloride diffusion coefficient (D) were reduced in the presence of MgSO4 mainly due to the effect of filling of pores with E. PPC-C exhibited better performance against ingress of chloride (Cl−) ions than that of O20FA-C followed by OPC-C. MS in exposure solutions reduced chloride binding. The concrete made with OPC exhibited higher chloride binding than O20FA followed by PPC.

A Neural Network-Based Prediction of Superplasticizers Effect on the Workability and Compressive Characteristics of Portland Pozzolana Cement-Based Mortars

Portland Pozzolana Cement (PPC) mortars are predominantly employed in plastering works to achieve better workability, superior surface finish, and higher fineness to offer better cohesion with fine aggregates than the ordinary Portland cement (OPC) mortars. To achieve high performance in the cement mortar similar to cement concrete, the addition of a superplasticizer is recommended. The present study investigates the impact of addition of sulphonated naphthalene formaldehyde- (SNF)-based (0.5%, 0.6%, 0.7%, and 0.8%) and lignosulphate- (LS)-based (0.2%, 0.3%, 0.4%, and 0.5%) superplasticizers on the workability and compressive strength characteristics of PPC mortars. Plastering mortars of ratio 1 : 4 were prepared with natural sand and manufacturing sand (M sand) as fine aggregates. A flow table test was conducted on all the mortar mix proportions, and the effects of the inclusion of superplasticizers on flow properties were recorded at different time intervals (0, 30, 60, 90, and 120 minutes). PPC mortar cubes were prepared, cured, and examined to assess the inclusion of chemical admixtures on compressive strength at different ages (1, 3, 7, 14, and 28 days). The experimental findings from the workability and compressive strength of PPC mortars were analyzed, and the corresponding results were predicted using artificial intelligence. Experimental investigations demonstrated that the desired flow characteristics and higher compressive strength results were achieved from a 0.7% dosage of ligno-based superplasticizer. The predicted workability and compressive strength results at various ages acquired by implementing an Artificial Neural Network (ANN) were found to be in close agreement with the experimental results.

Mechanical and Microstructure Properties of Plain and Blended Cement Structural Lightweight Aggregate Concrete Using Sintered Fly Ash Aggregates

Infrastructure and industry have grown dramatically as a result of globalization and urbanization. However, there are certain challenges, such as meeting infrastructural needs that require a large amount of extraction of natural aggregates and disposal of waste generated as a result of industrialization. Both of these challenges have an adverse impact on the environment. Deforestation, erosion, contamination of nearby streams, and increase in noise, dust, and emissions are all consequences of aggregate extraction. The industrial waste can contaminate groundwater, lakes, streams, rivers and coastal waterways and harm the land and neighboring water bodies. Hence these challenges must be addressed as a priority for environmental sustainability. The current study developed structural lightweight aggregate concrete (SLWAC) using sintered fly ash aggregate (SFA). The investigation was done with the use of different binders such as Portland Pozzolana Cement (PPC), Ordinary Portland Cement (OPC), and Micro Fibre Cement (MFC). The present study explores the suitable binder to produce SLWAC at different water-cement ratios of 0.4, a0.44, and 0.48. The performance evaluation of SLWAC was investigated by mechanical behavior like compressive strength, split tensile, flexural strength, and impact test. Microstructure analysis is also included in this study to validate the mechanical experiment results. SLWAC made from OPC shows more mechanical strength than PPC and MFC, due to faster hydration and early strength gain. SLWAC made from microfiber cement, has more strength as compared to PPC. This could be due to fibers in MFC, acting as a reinforcing agent, which reduces micro cracks. The microstructure of SLWAC shows that the wall effect does not exist in SLWAC compared to normal aggregate concrete. It has a uniform and continuous microstructure of hydration products and partially penetrates the SFA. It could be associated with the superior interfacial transition zone having a lower w/c ratio because of the higher absorption of SFA. The findings show that all developed SLWAC can be used in structural members like beams, columns, and slabs.

Ductility response of RC beams composed of limestone calcined clay cement (LC3) and polypropylene (PP) fibre

Ordinary Portland Cement (OPC) is distinguished by considerable pollutant emissions and excessive energy and resource consumption. The development of low-clinker blended Portland cement with mineral additives is the most practical and recognisable method of resolving these issues in the cement industry. The traditional OPC consists of 95% clinker. Supplementary Cementitious Materials (SCMs) enhance the OPC by lowering clinker production. To reduce CO2 emissions, an innovative low-carbon cement called Limestone Calcined Clay Cement (LC3) replaces clinker with additional cementitious ingredients (SCMs). Clinker (50): calcined clay, limestone, and gypsum are the primary sources of LC3 cement. Adding Polypropylene (PP) Fibre endorses ductility and reduces the shrinkage cracks. PP Fibre generates a three-dimensional random distribution network structure when mixed with concrete, significantly preventing the creation and growth of micro cracks. PP Fibre can keep water and other potentially hazardous ions out of concrete. The beam specimens were incorporated with a 1.5% volume fraction of PP Fibre randomly distributed through the section. This study focused on LC3 and PP Fibre on the ductility response of RC beams. RC beams tested for the study consisted of Reference RC Beam, Reference RC beam with 1.5% PP Fibre, RC Beam with LC3 cement, and RC Beam with LC3 cement & 1.5% PP Fibre. The size of RC beams is 100 × 150 × 1000 mm, and they underwent four-point bending testing until failure, and the maximum load were recorded. First crack load and first deflection, yield load and yield deflection, ultimate load and ultimate deflection, as well as ductility and failure mechanisms, are all studied parameters. The findings revealed that LC3 and Portland Pozzolana Cement have almost identical compressive strengths (PPC). The addition of 1.5% PP exhibited better performance appreciably. RC beam with 1.5% PP Fibre shows an ultimate strength of 8.0% compared to the Reference RC Beam.