Split Tensile Strength Research Articles

A comprehensive study on mechanical properties, durability, and environmental impact of fiber-reinforced concrete incorporating ground granulated blast furnace slag

Concrete pavements are integral to sustainable infrastructure, offering longevity and resilience in construction and transportation. This study focuses on optimizing concrete pavements through the incorporation of steel and carbon fibers with Ground Granulated Blast Furnace Slag (GGBS) to enhance mechanical strength, reduce fracture development, and minimize carbon emissions. Utilizing 25 mixing designs with a consistent water-to-cement ratio of 0.40, varying ratios of GGBS, steel fibers, and carbon fibers (0.5 %, 1 %, and 1.5 % based on concrete volume) were explored. A comprehensive evaluation, including slump, compressive strength, flexural strength, split tensile strength, water absorption, abrasion resistance tests, carbon dioxide emissions, and cost analysis, was conducted at different curing stages. Results revealed a decline in compressive strength for all mix designs at 28 days, attributed to reduced cement strength with GGBS substitution. The 1.5 % steel fiber and 50 % GGBS mix demonstrated minimal compressive strength reduction (30.1 MPa, 5.5 % less than control), outperforming other mixtures. Steel fibers surpassed carbon fibers, likely due to \\erior distribution. Notably, 1.5 % steel fibers showed superior results, particularly with 50 % GGBS. Compressive strength generally increased with GGBS content, except for 1 % fibrous samples where 40 % GGBS produced optimal results. At 90 days, compressive strength increased for most designs, with G50S1.5 exhibiting over 38 % growth compared to the control. Steel fiber-containing samples outperformed carbon fiber-containing ones, showcasing the efficacy of steel fibers in enhancing compressive strength. Split tensile strength generally decreased, but steel fibers improved it, emphasizing their positive influence. Flexural strength increased in 28 and 90 days, with steel fiber-containing designs outperforming. G30S1.5 showed the most significant increase (33.3 %) at 28 days, and G30S1.5 exhibited the highest growth (32.22 %) at 90 days. Abrasion resistance tests indicated steel fibers and GGBS positively impacted abrasion reduction. G50S1.5 demonstrated the highest abrasion resistance (25 % increase over control). The environmental evaluation revealed lower CO2 emissions for GGBS-containing designs. G50S0.5 showed a 40.34 % reduction compared to the control sample. Cost analysis showed GGBS reduced costs, but fiber addition, particularly carbon fibers, increased costs. G30C1.5 had the highest cost increase (208.5 %), while G50S1.5 showed a marginal rise (3.9 %) compared to the control. Therefore, steel fibers in concrete pavements offer improved mechanical properties, durability, and reduced environmental impact, making them a viable choice despite a slight increase in cost. Conversely, carbon fibers are cautioned against due to their higher cost and inferior mechanical properties.

The Effect of Partial Replacement of Cement with Diatomaceous Earth (DE) and Polypropylene Fibers (PPF) on Fresh, Hardened, and Durability Properties of Concrete

This research aims to investigate the fresh and mechanical properties of concrete with diatomaceous earth (DE) and polypropylene fiber (PPF). The cement was partially replaced by DE in the concentration ranging from 5 to 20% by weight; whereas, PPF was incorporated in concrete mix as in range of 0.05–0.20% by cement weight. Totally, 25 different mix proportions were developed and their fresh properties were examined using slump, density and compacting factor tests. Besides, mechanical properties were evaluated by. Using compressive, split tensile, and flexural strength analysis at the ages of 7th, 14th and 28th days. Furthermore, concrete durability properties were evaluated using water penetration, chloride permeability as well as sorptivity tests, which have been performed at the age of 28th day. The result exhibits that the incorporation of D.E slightly affects the slump value meanwhile PPF decreases the fresh values. Furthermore, the combination of DE and PPF in concrete significantly enhances the mechanical properties compared to the control mix. The mix proportion of 15% DE and 0.15% of PPF exhibited a noticeable influence on mechanical properties as well as durability properties compare to control concrete.

Early Strength of Concrete by using Ground Granulated Blast Furnace Slag and Local Ordinary Portland Cement Materials

It is well known that using Ground Granulated Blast Furnace Slag (GGBFS) to replace some of the cement in concrete will cause it to take longer to reach its ideal compressive strength. However, several precast concrete manufacturing processes require high initial compressive strength values to speed up production. The impact of partially substituting GGBFS for cement on the initial strength values of concrete is investigated in this work. The 300 concrete cylinder samples were used to accomplish the study's goals. Compressive and split tensile tests determined the concrete's initial compressive strength and split tensile strength outputs. Therefore, the ideal percentage of GGBFS can replace cement by 20–30% to achieve the desired early compressive strength of 16 MPa in 16 hours by setting the proper water-cement (w/c) ratio at about 0.25. Because a low w/c ratio leads to low workability, some additives, such as silica fume or superplasticizer, can be employed to further increase the workability and performance of concrete.

Influence of Recycled Aggregates and Silica fumes on Compression and Split Tensile Strength of Composite Materials

Influence of Recycled Aggregates and Silica fumes on Compression and Split Tensile Strength of Composite Materials

Effect of the Specimen’s Height on the Split-Tensile Strength of the Fibers Reinforced Clay-Lime-Rice Husk Ask Mixture

Effect of the Specimen’s Height on the Split-Tensile Strength of the Fibers Reinforced Clay-Lime-Rice Husk Ask Mixture

Utilization of Waste Materials for Making Plastic Bricks

Currently, due to urbanization, there has been a notable rise in the use of plastic in our daily lives, owing to its widespread utility and popularity. However, its non-biodegradable nature presents a significant drawback. One potential solution for recycling plastic waste involves creating plastic bricks by blending plastic with sand, offering a substitute for conventional bricks. The primary challenge lies in managing plastic waste, particularly as continued reuse of PET bottles carries the risk of carcinogenic transformation, with only a small percentage currently being recycled. To address this issue, PET bottles are meticulously cleaned and combined with fine aggregate (sand) at various ratios (3:7, 2:3, 1:1) to produce high-quality brick blocks with excellent thermal and acoustic insulation properties. This environmentally friendly approach tackles the non-biodegradability problem of plastics while reducing the overall cost of construction and pollution. The resulting bricks exhibit high compressive strength, minimal water absorption, and thermal resistance, rendering them suitable for diverse applications. Increasing the sand-to-plastic ratio enhances the strength of the bricks, ensuring durability with minimal water absorption and no efflorescence. This method shows promise in recycling plastic waste and mitigating its environmental impact. Furthermore, various tests including split tensile strength test, penetration test, and specific gravity were conducted to validate the efficacy of the approach. Key Word: PET (polyethylene terephthalate), compressive strength, water absorption, split tensile strength test, efflorescence, specific gravity test

Utilizing an enhanced machine learning approach for geopolymer concrete analysis

ABSTRACT The flyash-based geopolymer concrete has been extensively utilized to minimize carbon emissions for over 15 years. The compressive strength (CS), split tensile strength (STS), and flexural strength (FS) of concrete determine its mechanical characteristics. Laboratory strength testing and analytical methods is costly and time-consuming, which struggle to predict complicated concrete combination CS, STS, and FS. ML models accurately predict CS, STS, FS. To predict the CS, STS, and FS of GPC concrete, five ML techniques (LR, SVM, GPR, EL, and ANN) were adopted. Taylor diagrams and error graphs adopted to represents model performances. The GPR outperforms other models in CS predictions by having the lowest MAE, RMSE, MAPE, and R-values. GPR continues to outperform in STS predictions, with low MAE, RMSE, and MAPE, as well as high R-values. GPR outperforms FS predictions with low MAE, RMSE, MAPE, and high R-values. SVM is excellent since it has a low MAE and RMSE. SVM, GPR, and ANN optimisations keep them competitive. GPR consistently gets the lowest MAPE values across all three tests, indicating that it is a strong model contender. The created model can forecast the mechanical characteristics of geopolymer concrete with ease and better reproducibility.

Self-healing of macroscopic cracks in concrete by cellulose fiber carried microbes

This research introduces a new approach to healing millimeter scale cracks in concrete using Lysinibaccilus Sphaericus Bacteria (LSB) encapsulated in cellulose fibers. Cracking in concrete, particularly macroscopic cracking, can cause premature structural failure and reduce its lifespan, which is a critical industry challenge. While bacteria encapsulated in cellulose fibers have been used to heal cement mortar, the studies are limited to heal much narrower cracks. In this study, we integrate LSB, known for its strong biocalcification abilities, with the protective environment of cellulose fibers, which are renewable and sustainable, for healing millimeter scale cracks in ordinary cement concrete. To understand the healing process, we firstly used a 3D-printed polymeric scaffold for preliminary observations of calcite precipitation, demonstrating the potential of bacteria-induced calcification in a controlled environment before applying these insights to concrete. We then studied the self-healing of concrete. Through mechanical testing, we identified the optimal concentration of cellulose fiber as 0.45 % by volume of mortar. Approximately 2.38 × 108 bacteria were immobilized in each gram of cellulose fibers. With cellulose fiber encapsulated LSB, the test results show up to 25 % increase in compressive strength and split tensile strength. After crack healing, the self-healing concrete still has higher mechanical strength than the undamaged control concrete. Particularly, the self-healing concrete was able to heal cracks up to 2.5 mm wide in fully wet environments and 1.5 mm wide in wet-dry conditions. This research also highlights the resilience of bacteria carried by cellulose fibers against harsh environmental conditions, including high temperatures at 160 °C, ensuring the durability and applicability of the proposed self-healing concrete in diverse climates. Integrating cellulose fibers encapsulated LSB into concrete represents a significant breakthrough in addressing the perennial problem of concrete cracking, offering a promising avenue for constructing durable and maintenance-free structures.

Performance assessment of blended self-compacting concrete with ferrochrome slag as fine aggregate using functional ANOVA

The current study explored the feasibility of re-use of ferrochrome slag (FS), a waste byproduct from the ferrochrome industry as a replacement to fine aggregate in self-compacting concrete (SCC) with cement and fly ash as binders. The study investigated the mechanical and durability characteristics of SCC of M25 grade, incorporating FS in lieu of fine aggregate, up to 60 % replacement levels. Albeit workability of fresh concrete decreased with the increase of FS content, they were within the recommended limits of EFNARC for SCC. Considerable decreases in compressive, tensile and flexural strengths were observed in the mixtures with FS contents above 40 %. Slightly better performances in terms of water absorption, sorptivity, chloride ion permeability and sulphate attack were found in the concretes partially blended with FS. Leaching of chromium (Cr) from FS-incorporated self-compacting concrete samples were within the Indian discharge limits. Microstructural studies were conducted to decipher the arrangement of components in the concrete as well as determine the elemental composition of ferrochrome slag. Functional analysis of variance (ANOVA) was conducted to determine the significance of functional components in explaining the variability of the mechanical properties expressed as continuous functions. The test findings indicate that there is no statistical difference in the compressive strength and split tensile strength as a result of substituting a portion of sand with FS. Nevertheless, a rise in flexural strength is noticed after surpassing a 5 % substitution.

Effectiveness of areca fiber and cement on the engineering characteristics of compressed stabilized earth blocks

This study investigates the potential of integrating areca fiber as a reinforcement agent in Compressed Stabilized Earth Blocks (CSEBs), used in combination with cement. Traditional earth-based construction methods, once prevalent, have seen a decline in industrialized nations with the advent of modern building materials. However, there is a growing resurgence in the use of earth-based materials, motivated by their economic, social, and environmental sustainability benefits. This renewed interest in CSEBs is primarily due to their superior energy efficiency and lower greenhouse gas emissions, especially when compared to conventional materials like fired clay bricks or concrete blocks. Areca catechu, widely recognized as the areca palm, thrives in the tropical regions of the Pacific, Asia, and East Africa. The fibers derived from areca nutshells, often regarded as agricultural waste, present an intriguing material for study. While the application of areca fiber in soil reinforcement has been previously acknowledged in scholarly literature, its specific role in enhancing the engineering properties of CSEBs represents a novel area of exploration, which this research aims to address comprehensively. In this research endeavor, CSEBs were manufactured with varying proportions of areca fibers, spanning from 0 % to 3 %, based on the dry mass of soil. Subsequently, these blocks underwent comprehensive testing to assess their strength and durability characteristics. Strength properties were evaluated through unconfined compression, split tensile strength, and flexural strength tests, while durability was meticulously examined using wet strength, water absorption, submersion, and efflorescence tests. Here, CSEBs displayed increases in compressive strength (107.04–436.38 %), split tensile strength (208.66–358.08 %), and flexural strength (16.49–82.47 %). Durability tests revealed enhanced wet compressive strength (up to 100.42 % increase) and optimized water absorption rates. A notable finding is identifying 2 % areca fiber content as optimal, yielding significant improvements in strength and durability parameters. Microstructural analysis using Scanning Electron Microscopy (SEM) further confirmed the benefits of 2 % fiber content, showing a compact and cohesive internal structure with reduced voids and fissures. This microstructural integrity underlines the enhanced bonding and stability imparted by the areca fibers. Another essential aspect of the study was evaluating the compliance of CSEBs with various international standards on earthen construction. The fiber-reinforced blocks met or exceeded several standards, demonstrating their suitability for broader construction applications. Finally, this study underscores the promise of areca fiber as a valuable reinforcement material in CSEBs stabilized with cement. This innovative approach offers a sustainable and eco-friendly building material option, aligning with the growing emphasis on environmentally conscious construction practices.

Utilisation of Waste Shea Nutshell Fine-Grained Particles to Enhanced Strength and Durability Behaviour of Concrete

Shea nutshells possess properties that stabilise soil enough to resist water penetration. It is a waste material and incorporating it as an additive material in concrete will be a means by which it can be recycled. With this projection, the study incorporated shea nutshell particles (SSP) as fine aggregates in concrete. The aim was to determine their influence on strength and durability properties. Fine aggregates were partially replaced with 0%, 10%, 20%, 30%, and 40% SSP based on the weight of the aggregate, and labelled as A0, S10, S20, S30 and S40 respectively. Concrete cubes of size 150 mm and cylinders of diameter 150 mm and height of 300 mm were prepared and cured for 7, 14, 28, and 90 days. The concrete was tested for density, compressive strength, split tensile strength, water absorption, and sulphate attack. The inclusion of the SSP did not improve the compressive and split tensile strengths. However, water absorption and sulphate attack decreased with further addition. Though, strength properties did not appreciate, values at 10%, 20% and 30% additions in 28 and 90 days satisfied the 28 days minimum requirement of 25 N/mm2. Hence, the study recommends the use of SSP in concrete production up to 30%.

Effect of High Temperatures on Mechanical and Shielding Properties of Lead–Zinc Tailings Concrete for Radiation Protection

Due to the high prices, the popularity of radiation shielding concrete (RSC) has been greatly limited. To solve this, this research reused the lead–zinc tailings (LZT) as a fine aggregate replacement ranging from 0% to 60% for the RSC. The results revealed that the RSC containing 30% LZT presented better workability and achieved 95.84% of the compressive strength and 98.49% of the linear attenuation coefficient of the RSC, and reached the highest splitting tensile strength values, which increased by 4.43%. Meanwhile, after the heat treatments, there were favorable correlations between the relative velocity and relative strength, as well as between the damage index and the relative linear attenuation coefficient, which could accurately reflect the degradation of not only the mechanical but also the shielding properties. Considering the temperature and shielding thickness, the reuse of LZT can bring considerable economic and environmental benefits.

Mechanical Properties of a Sustainable Low-Carbon Geopolymer Concrete Using a Pumice-Derived Sodium Silicate Solution.

A geopolymer is an inorganic amorphous cementitious material, emerging as an alternative sustainable binder for greener concrete production over Ordinary Portland Cement (OPC). Geopolymer concrete production promotes waste reuse since the applicable precursor materials include agricultural and industrial waste that requires disposal, helping to reduce waste in landfills and ensuring sustainable environmental protection. This study investigates the development of an environmentally friendly sodium silicate alternative (SSA) derived from pumice powder (PP) in place of a commercial Na2SiO3 solution at a 10 M concentration. Six concrete batches were produced at alkaline/precursor (A/P) ratios of 0.1, 0.2, 0.3, 0.4, and 0.5. The geopolymer mix AF4, with an A/P ratio of 0.4, became the optimum geopolymer concrete design; however, it recorded lower compressive, tensile splitting, and flexural strengths, respectively, against the control OPC concrete. The geopolymer formulations, however, obtained 28-day-hardened concrete densities comparable to the control concrete. The 28-day compressive strength of the OPC concrete was 29.4 MPa, higher than the 18.8 MPa recorded for AF4. However, the 56-day strength of AF4 improved to 22.4 MPa, an around 19% increase compared to the 30.8 MPa achieved by the control mix on day 56, having experienced only a 5% strength increase. The low mechanical performances of the geopolymer formulation could be attributed to extra water added to the original geopolymer design to improve the workability of the geopolymer mix. Therefore, the SSA alkaline solution using PP showed some potential for developing geopolymer concrete for low-strength construction applications.

Influence of recycled coarse aggregate on properties of fly ash and slag-based geopolymer concrete cured under oven and ambient temperature

Purpose The purpose of this paper is to investigate the effect of the replacement of natural coarse aggregate (NCA) with different percentages of recycled coarse aggregate (RCA) on properties of low calcium fly ash (FA)-based geopolymer concrete (GPC) cured at oven temperature. Further, this paper aims to study the effect of partial replacement of FA by ground granulated blast slag (GGBS) in GPC made with both NCA and RCA cured under ambient temperature curing. Design/methodology/approach M25 grade of ordinary Portland cement (OPC) concrete was designed according to IS: 10262-2019 with 100% NCA as control concrete. Since no standard guidelines are available in the literature for GPC, the same mix proportion was adopted for the GPC by replacing the OPC with 100% FA and W/C ratio by alkalinity/binder ratio. All FA-based GPC mixes were prepared with 12 M of sodium hydroxide (NaOH) and an alkalinity ratio, i.e. sodium hydroxide to sodium silicate (NaOH:Na2SiO3) of 1:1.5, subjected to 90°C temperature for 48 h of curing. The NCA were replaced with 50% and 100% RCA in both OPC and GPC mixes. Further, FA was partially replaced with 15% GGBS in GPC made with the above percentages of NCA and RCA, and they were given ambient temperature curing with the same molarity of NaOH and alkalinity ratio. Findings The workability, compressive strength, split tensile strength, flexural strength, water absorption, density, volume of voids and rebound hammer value of all the mixes were studied. Further, the relationship between compressive strength and other mechanical properties of GPC mixes were established and compared with the well-established relationships available for conventional concrete. From the experimental results, it is found that the compressive strength of GPC under ambient curing condition at 28 days with 100% NCA, 50% RCA and 100% RCA were, respectively, 14.8%, 12.85% and 17.76% higher than those of OPC concrete. Further, it is found that 85% FA and 15% GGBS-based GPC with RCA under ambient curing shown superior performance than OPC concrete and FA-based GPC cured under oven curing. Research limitations/implications The scope of the present paper is limited to replace the FA by 15% GGBS. Further, only 50% and 100% RCA are used in place of natural aggregate. However, in future study, the replacement of FA by different amounts of GGBS (20%, 25%, 30% and 35%) may be tried to decide the optimum utilisation of GGBS so that the applications of GPC can be widely used in cast in situ applications, i.e. under ambient curing condition. Further, in the present study, the natural aggregate is replaced with only 50% and 100% RCA in GPC. However, further investigations may be carried out by considering different percentages between 50 and 100 with the optimum compositions of FA and GGBS to enhance the use of RCA in GPC applications. The present study is further limited to only the mechanical properties and a few other properties of GPC. For wider use of GPC under ambient curing conditions, the structural performance of GPC needs to be understood. Therefore, the structural performance of GPC subjected to different loadings under ambient curing with RCA to be investigated in future study. Originality/value The replacement percentage of natural aggregate by RCA may be further enhanced to 50% in GPC under ambient curing condition without compromising on the mechanical properties of concrete. This may be a good alternative for OPC and natural aggregate to reduce pollution and leads sustainability in the construction.

Effect of nano SiO2 on rheology, nucleation seeding, hydration mechanism, mechanical properties and microstructure amelioration of ultra-high-performance concrete

The use of Nano SiO2 products will likely change cement, concrete construction sector. Their stability, low toxicity, and ability to functionalise with chemicals and polymers have drawn interest. When mixed with hybrid nanomaterials, nanostructured silica with unique geometric properties can improve biomaterial conjugates. Few scientists have studied the effects of Nano SiO2 on cement-based composites microstructural characterisation and mechanical behaviour. In this study four combinations were made by adding 0%, 1%, 2%, and 3% Nano SiO2 by cement weight. The tested Ultra-High-Performance Concrete (UHPC) mixes with various mechanical and microstructural characterisation techniques utilised. The finding suggests that the UHPC mixture with 2% Nano SiO2 has better mechanical and microstructural capabilities than the others. The study found that UHPC samples with more Nano SiO2 had higher mechanical strength than the reference sample. The study found that adding UHPC 2% Nano SiO2 to the mix increased compressive, split tensile, and flexural strength by 56%, 37%, and 28%, respectively. In UPV testing, this UHPC NS-2% mix had the greatest average velocity 4883 m/s and 4951 m/s for 28 and 90 days, suggesting a stronger concrete matrix. In optimum UHPC mix due to nucleation effect of Nano SiO2 and hydration of cement generates to more Calcium Silicate hydrate gel formation and less ca/si ratio is 0.54. It will lead to produce the dense UHPC with lowest porosity. The environmental and economic benefits of UHPC with Nano SiO2 make it a suitable building material for various civil engineering applications.

Response Surface Optimization of Rice and Guinea Corn Husk Ash Blended Concrete

Concrete, a fundamental construction material, consists of aggregates, water, cement, and additives. Unfortunately, the large-scale production of cement is a major contributor to carbon dioxide (CO2) emissions, primarily from the manufacturing process and the consumption of fossil fuels. This not only incurs environmental costs associated with global warming but also depletes vital limestone deposits. To mitigate these issues, this study aims to explore the optimal utilization of Guinea Corn Husk Ash (GCHA) and Rice Husk Ash (RHA) in concrete. This research investigated the chemical properties of GCHA and RHA, and their impact on the compressive and split-tensile strengths of concrete when integrated in various proportions. The study reveals that both GCHA and RHA meet the minimum oxide content requirement of 70% set by ASTM C618, with silicon dioxide (SiO2) as the predominant oxide. Increasing the content of RHA and GCHA from 5% to 10% improves the concrete's compressive and split-tensile strengths after curing for 56 days. Optimization results indicate that the ideal mix consists of 10% GCHA, 8.5% RHA, and 82.5% cement, yielding a compressive and split tensile strength of 31.34 N/mm² and 3.07 N/mm² respectively. This study thus offers a promising solution for sustainable concrete production by reducing the environmental footprint of cement while enhancing material properties and promoting an eco-friendlier approach to construction. Keywords: Concrete, Guinea Corn Husk Ash, Rice Husk Ash, Compressive Strength, Split-Tensile Strength

Assessing Novel Fiber Reinforcement Against Conventional Mix by Using Both Natural and Synthetic Fibers in Concrete with Statistical Performance Analysis

This research investigates the effect of incorporating innovative human hair fibers (HHF) and polypropylene fibers (PPF) into concrete, which has been observed to enhance the material’s strength characteristics. These fibers augment the concrete’s tensile strength and resilience, fortifying it against cracks and elevating its overall endurance. This research delves into the impact of reinforcing concrete specimens with human hair and polypropylene fibers. These specimens are employed in cube, cylinder and flexural beam tests. Both fresh and hardened properties, such as compaction factor and slump, and compressive, split-tensile, and flexural strength at varying curing periods (28 days and 90 days) and the ratios (1%, 2%, and 3%) are considered by weight of cement. Specifically, the 3% polypropylene fiber concrete mix exhibited the highest average compressive strength at both 28 and 90 days, while the 2% polypropylene fiber mix showed the highest split-tensile strength. Flexural strength results followed a similar trend. Results show that 3% HHF addition leads to notable improvements in concrete strength properties, albeit not as significant as with polypropylene fibers. Statistical analysis, including independent samples Kruskal–Wallis tests, was conducted to compare the distributions of strength values across different groups. The statistical analysis indicates significant differences in strength distributions across groups, with p-values below the significance level of 0.05. This underscores HHF’s potential as a sustainable alternative in construction applications, contributing to enhanced concrete strength.

Effect of Silica Fume Addition on Mechanical Properties of Concrete in Peat Swamp Water Environment

Hydraulic Portland cement, water, fine and coarse aggregate, and additional ingredients can be added or left out to create concrete. Making and maintaining concrete requires water as a reagent in the cement mixture so that a chemical reaction occurs when it undergoes the hydration process, which is the process where the cement begins to bind the ingredients that make up the concrete and then hardens and forms a solid mass. The need for water in concrete care is to soak it during the hardening process, however, not all types of water can be used. Peat swamp water is water that collects or flows within the peat swamp ecosystem. Peat swamps are a type of swamp formed from organic material accumulated over thousands of years. Silica fume is a material that contains SiO2 greater than 85% and is a very smooth, round material with a diameter of 1/100 the diameter of cement. The swamp water used in this research was taken from Jl. Rappokalling, Tallo District, Makassar City, South Sulawesi. Mix Design uses the Indonesian National Standard (SNI) 03-2834-2000 method with a planned concrete quality (f'c) of 25 MPa. Compressive strength tests were performed on concrete that was 7 and 28 days old for split tensile strength, and on the 28-day old concrete for modulus of elasticity. The concrete's compressive strength ratings after 28 days in variations of immersion in normal water and peat swamp water are 25,842 MPa and 20,749 MPa. From the test results, it was found that the average split tensile strength value of concrete for variations in normal water immersion and peat swamp water was 2.545 MPa and 1.886 MPa. From the results of the modulus of elasticity test, it was found that the average concrete in normal water immersion and peat swamp water variations was 19893.961 MPa, and 17109.75 MPa.

Assessment of mechanical and durability properties of FA-GGBS based lightweight geopolymer concrete

The relentless consumption of natural aggregates and cement in concrete due to rapid construction has resulted in the exhaustion of natural resources; consequently, it's vital to create environment friendly building materials and implement sustainable construction methods. The development of geopolymer concrete (GPC) is a step towards the utilization of by-products. This study aims to prepare and assess the durability and mechanical characteristics of fly ash (FA) and ground-granulated blast furnace slag (GGBS)-based lightweight geopolymer concrete (LWGC). Utilizing sintered fly ash aggregate (SFA) in GPC is one such approach that can lower the usage of regular cement and natural aggregates. In the present investigation a total of six GPC mixes were prepared with varying alkaline activator to binder (AA/B) ratios of 0.3–0.8. The results shows that the AA/B ratio and the mechanical characteristics of LWGC samples are inversely related. The mechanical properties exhibits maximum strength at the lowest AA/B ratio. The LWGC achieved the highest compressive strength (CS) of 48.9 MPa, modulus of elasticity (EM) of 27.3 GPa, split tensile strength (STS) of 3.9 MPa, and direct shear strength of 5.4 MPa after 28 days of ambient curing. The oven dry density (OD) ranged from 1722–1805 kg/m3, satisfying the various codal provisions to be considered a lightweight concrete (LWC). The durability study indicates that for structural applications, the performance is satisfactory, especially in acidic conditions. SEM and EDS analyses also infer strong mechanical and durability characteristics. The obtained results suggests that LWGC is a possible material for structural concrete applications.

Optimizing Concrete Mixtures with Red Soil as a Partial Fine Aggregate Replacement: an In-depth Investigation

An experimental investigation is carried out to study the behavior of concrete by replacing the fine aggregate with locally available red soil. It involves a certain test to find the quality improvement of concrete when red soil is added to it. The partial replacement of sand with red soil has been done according to the specific mix proportion to gain good strength in concrete. In past studies of the journal main problem arising that increase of red soil is to reduce the strength of concrete and it absorb more amount of water. In this project, it is preferred to analysis the strength of M20 Concrete and the amount of red soil is to be added in following percentage such as 15%, 30% & 45%. Mechanical properties such as compressive strength, split tensile strength, flexural strength tests have been carried out for red soil mixed concrete and plain concrete to differentiate the strength and imperviousness in it. The tests are done during 7th, 14th & 28th days after curing.