Higher Compressive Strength Values Research Articles

Kepah Shell Waste as A Coarse Aggregate Substitution Material on Concrete Mixture

This research uses kepah shell waste as a substitute for coarse aggregate. The purpose of this study is to determine the value of slump and compressive strength values in concrete variations. Variations of concrete consist of normal concrete, mixed shells of waste concrete with 5%, 10%, and 15% substitution of coarse aggregate. The concrete maintenance period was carried out for 7 days, 14 days, and 28 days. The results of the slump value research show that the lowest slump value is normal concrete, while the highest slump value is concrete with a mixture of 15% kepah shell waste. For the results of the compressive strength value, the highest compressive strength value is concrete with a mixture of 5% kepah shell waste. For the most economical cost with high quality of concrete compression strength is the concrete mixture with 5% of kepah shell waste. The greater the percentage of kepah shell waste, the cheaper the concrete price, but higher percentage of kepah shell waste will result a decrease in the quality of concrete.

Analysis of Environmentally Friendly Concrete (Green Concrete) Using Coal Fly Ash as a Substitute Material for Portland Cement in Road Pavement

The development of technology in the field of construction, especially in concrete technology, is now becoming more rapid, which requires concrete materials that can adapt to the times. As well as for energy savings from normal concrete materials from a mixture of fine, coarse, cement and water can now be added to other materials. In this era, the use of cement for concrete making materials is very identical, therefore to reduce the use of cement, it is necessary to mix other materials. The research method that researchers use is the experimental-laboratory method by making test objects in the form of concrete cylinders with a size of 15x30 cm. Analysis of concrete testing using Fly Ash mixtures in this study there are several variations of fly ash mixtures, namely fly ash 50%, 60%, and 70%. In testing several Fly Ash mixtures produced a compressive strength value of 50% Fly Ash percentage and 2% Accelerator of 161.630 kg/cm2, 60% Fly Ash and 2% Accelerator of 154.189 kg/cm2, 70% Fly Ash and 2% Accelerator of 92.670 kg/cm2. In the results of this study with several variations of fly ash mixtures, the highest compressive strength value was obtained at a percentage of Fly Ash 50% and Accelerator 2%, which amounted to 161.630 kg/cm2 with the first variation test specimen sample at the age of 28 days of concrete.

Impact of Recycled Polypropylene Fibers on the Density and Strength of Unreinforced Concrete

Polypropylene (PP) is widely used in the construction industry to produce a variety of materials. Accordingly, a huge amount of waste is produced during or after the construction activity. The PP fiber provides a good alternative solution to enhance concrete properties and more sustainable concrete produced in terms of isolation and weight reduction. In this study, 24 concrete cubic samples are cast by adding different PP fiber content to characterize this fiber effect on concrete density and unconfined compressive strength (UCS). The results demonstrate that using higher fiber content of 2%, 6%, and 10% leads to a mass reduction that equals to 59, 157, and 290 kg compared to normal concrete per one cubic meter. However, at higher PP fiber content, the unconfined compressive strength decreases compared to the controlled samples. The concrete mix with 2% PP fiber revealed a higher value of compressive strength with increment by (10-12)% at age (7-28) days compared to normal concrete. The outcomes imply that using PP fiber contributes to the protection of the environment by reducing the quantity of PP waste from construction materials.

Mechanical properties and microstructure of brick aggregate concrete with raw fly ash as a partial replacement of cement

In response to environmental concerns, researchers explore fly ash as a cement replacement material, and crushed bricks as a cost-effective and load-reducing aggregate, particularly where stone chips are scarce. Therefore, this study investigates the mechanical properties and microstructure of brick aggregate concrete (BAC) with raw fly ash (FA) as a partial replacement of cement. The research involved casting raw FA based BAC (FBAC) cylinders (100 mm diameter and 200 mm height) and prism (100 × 100 × 500 mm) with varying levels of FA (0–25%) using a constant mix proportion by volume of 1:1.5:3 (cement : fine aggregate : coarse aggregate) with a water to binder (w/b) ratio of 0.50 and three curing ages (7, 28, and 90 days). Tests for mechanical properties, including compressive strength, split tensile strength, flexural strength, modulus of elasticity, and Poisson's ratio were conducted to assess the behavior of FBAC, and microstructure were then investigated at 28 days. The results indicated that increasing the FA content up to 15% led to gradual improvement in compressive strength and tensile strength values. At 28 days, the highest values of compressive strength and split tensile strength were observed at 10% FA, with 7.9% and 14.2% increase, respectively, compared to the control concrete. However, the flexural strength of FBAC decreased gradually with cement replacement. On the other hand, modulus of elasticity and Poisson's ratio increased gradually up to 20% and 25% cement replacement, respectively. Up to 15% FA enhanced a more uniform and compact microstructure than that of control concrete. Several equations have been developed to express relationship between compressive strength and other mechanical properties of FBAC. Hence, up to 15% raw FA as a partial replacement of cement improved the mechanical properties and microstructure of BAC.

EFFECT OF ADDING RED AND YELLOW PIGMENTS TO GEOPOLYMER CONCRETE

This study examined the feasibility of producing colored geopolymer concrete using slag as the binder and investigated the effects of pigment on various properties of geopolymer concrete. The geopolymer concrete was supplemented with two varieties of pigment, namely iron oxide hydroxide in the shades of "red" and "yellow", then the following tests of compressive strength, rebound number, density, and ultrasonic pulse velocity were carried out on it. The highest compressive strength value was achieved when adding 1% of pigments, which increased the red and yellow values from the reference value by 2.7 percent and 1.8 percent, respectively. The best rebound number values can be obtained by adding 1% yellow and 3% red, which increased the red and yellow values from the reference value by 8% and 15%, respectively. The density increases as the proportion of the additional pigment rises. The maximum density values were achieved by incorporating 1% of red and yellow pigment, with a respective increase of 1% and 3% for red and yellow. The highest values of ultrasonic pulse velocity when adding 1% of yellow and red color pigments increased by 1.7% for yellow and 2% for red. The optimal addition is 1.2% as it enhances properties and reduces expenses when utilizing smaller pigments.

Designing Hollow Brick Waste Based Alkali Activated Composites by Taguchi Method

The use of waste materials in alkali-activated material technologies is important in terms of sustainability. The production of alkali-activated composites (AAC) with hollow brick waste (HBW) as a binder may contribute to solving existing environmental problems related to the depletion of natural resources. In this study, mortars were produced using different concentrations (6 M, 8 M, and 10 M NaOH) and Alkaline Activator/Powder Material (AA/PM) ratios of 0.30, 0.35, and 0.40 through the alkali activation method. The hollow brick waste (HBW) powder was obtained by grinding inactive bricks in brick factories. The prepared mortars were cured separately for each mixture at 90°C for 24 hours. Compressive and flexural strength tests were performed on the prepared perforated hollow brick waste-based composites. The Taguchi method was used to determine the optimum mixing ratios by conducting compressive and flexural strength tests on the produced AAC. To optimize the parameters determined using the Taguchi method, the best mixing ratios were determined using the L9 (3^2) orthogonal index. The compressive and flexural strengths of the mixtures were evaluated considering the signal to noise ratio "larger the better" and the highest compressive strength value was 63.669 MPa and the highest flexural strength value was 6.629 MPa according to the optimum values. According to the obtained results, it was determined that the AAC produced at 6 M NaOH and 0.30 AA/PM ratio exhibited the highest compressive and flexural strength values.

Comparative Analysis of Strength of Differently Activated Denture Base Materials Including Recent Acetal Resin-Based Biodentaplast.

The aim of this study is to comparatively analyse the compressive and tensile strength of different types of record base materials made of different materials and processing techniques. The compressive and tensile strength of 4 types of injection moulded materials were compared with a control of conventional compression moulded material. Twenty test specimens (10 tensile and 10 compressive) were fabricated from each material. A test was done using the Instron 3382 (Norwood, MA, USA) universal testing machine. Compressive and tensile test values showed significant differences between the record base resin groups tested for both compressive and tensile strength tests (p=0.00). The mean tensile strength value was greatest for Group V (66.0 MPa) and lowest for Group III (41.9MPa) and the mean compressive strength value was greatest for Group I (74.5 MPa) followed by Group V (70.2 MPa) and lowest for Group III (10.8 MPa). Injection moulded acetal resin showed the highest tensile strength value; it was comparable to that of conventional compression moulded polymethyl methacrylate (PMMA). Compression moulding is reported to have the highest compressive strength values followed by injection moulded acetal resin material. Injection moulded acetal resin material attributed to its advantages and superior strength value, can be used as a material of choice in various clinical scenarios.

Analisis Kuat Tekan Beton dengan Pemanfaatan Silica Fume dan Fly Ash Sebagai Pengganti Semen Sebagian

Construction activities require concrete as a widely used material. Concrete consists of several compositions, namely fine aggregate, coarse aggregate, water, and Portland cement as the main material for the binder. Cement production contributes around 6% of carbon emissions which can damage the environment, including global warming, and the use of high levels of cement material in concrete mixtures, so alternative materials are needed to replace cement or cement additives for concrete mixes. Alternative materials used in this research are fly ash and silica fume. This research aims to determine the test results and characteristics of concrete using silica fume and fly ash as partial cement substitute materials as well as the effect of the ratio of silica fume and fly ash on the compressive strength of concrete. The research was carried out by direct testing in the laboratory. The various mixtures of Fly Ash (FA) and Silica Fume used are: FA 10% and SF 5%, FA 15% and SF 5%, FA 20% and SF 20%, FA 25% and SF 10%. Based on the results of compressive strength tests carried out at 28 days of concrete, it shows that the use of silica fume and fly ash to replace cement cannot be said to have succeeded in increasing the strength of the concrete. The highest compressive strength value was achieved by variation 3, namely with a fly ash content of 20% and 10% silica fume, producing a compressive strength value of 19.44 Mpa, this shows that the strength achieved is still limited to low quality concrete below 20 Mpa.

Experimental study of concrete mixes using crushed and uncrushed coarse aggregates by adopting ACI and DoE methods

AbstractThe main objective of this research is to investigate experimentally the effect of crushed and uncrushed coarse aggregate on the properties of hardened concrete (compressive strength) by adopting the American Concrete Institute (ACI) and the British Department of Environment (DoE) methods. Concrete mixes were designed, concrete cubes and cylinders were prepared and casted by using DoE and ACI respectively. DoE concrete design method considers both types of aggregates; crushed and uncrushed, while the ACI method does not take into account the effect of uncrushed coarse aggregate in design provisions. Then compressive strength tests of concrete samples were determined at ages of 7 and 28 days full curing period. The results obtained show that ACI gave higher values of compressive strength than that obtained by DoE for M30 and M40 except M25, which resulted in lower values than that obtained by DoE for crushed coarse aggregates. The 7-day compressive strength represents 75% of the 28-day compressive strength for ACI method, whereas in DoE reaching up to 73% and 77% for crushed and uncrushed coarse aggregate, respectively.

Mechanical strength and Life Cycle Assessment (LCA) of soil-cement: comparison between mixtures of soil with ASTM type III cement, LC3, and the incorporation of by products and agroindustrial residues

Soil stabilization with binders is based on the binder action on soil particles, in turn causing an improvement in the mechanical behavior of the soil. Thus, this study aims to analyze the mechanical and environmental properties of soil-cement mixtures using Portland ASTM type III cement as binders and comparing to LC3 (Limestone Calcined Clay Cement), as well as incorporating extra raw materials such as silica fume, fly ash, sugarcane bagasse ash (Saccharum officinarum L) and açai seed ash (Euterpe precatoria Martius). The mixtures of soil, binder, extra raw materials were performed manually, and the cylindrical specimens (100 mm internal ø) were molded based on the AASHTO Normal Test. The results showed that the highest values of compressive strength ranged between 10 and 11 MPa, which were recorded for reference, soil-LC³ and soil-LC-açai seed ash mixtures. Life Cycle Assessment (LCA) was performed using the CML 2001 method with the aid of the OpenLCA software. Additionally, it was observed that the main emissions and consequences for the environment were from mixtures containing higher clinker contents.

Effect of initial curing conditions on the durability performance of low-calcium fly ash-based geopolymer mortars

Geopolymer composite production has become an indispensable product to reduce carbon dioxide emissions, which have become an important problem today, and to provide green sustainability. Concerns about the global climate change problem have also accelerated geopolymer studies. This research investigated the mechanical and durability characteristics of low-calcium fly ash (LCFA) based geopolymer mortars with different curing temperatures and times. Two forms of curing conditions were applied; the first one was standard curing at room temperature (20±3°C and RH 65±10%) and the second one was cured in the hot air at 40°C, 60°C, and 80°C for 24h, 48h, and 72h followed by standard curing. After all curing processes, compressive strength, flexural strength, water absorption, void ratio, resistance to elevated temperatures, and freeze–thaw conditions were determined experimentally. In addition, SEM analysis was performed before and after durability tests for comparison purposes. Also, XRD and TGA analyzes were performed. According to test results, curing specimens at longer times and higher temperatures has been shown to increase compressive strength results. The highest compressive strength value was reached at 80°C after 72h of curing. Geopolymer specimens subjected to elevated temperatures (600°C and 900°C) lost a significant part of their strength value. After the freeze–thaw test, LCFA-based geopolymer specimens showed more than 70% resistance. The freeze–thaw resistance of geopolymer samples was positively affected on long-term curing at high temperatures, but high-temperature resistance was impacted negatively.

Optimalisasi Temperatur Sintering Pada Sintered Body Hidroksiapatit Dengan Penambahan Silika Sebagai Material Penguat

Sintered body hydroxyapatite (HA) in the form of pellets has been made by adding silica as a reinforcing material (ratio 60:40 wt.%) by varying the sintering temperature. HA and silica were subjected to a dry mixing process for 2 h, then a wet mixing process was carried out for 2 h with the addition of PVA and alcohol as a binder. The mixing process uses a rotary drum with the addition of zirconia balls with the aim of making the mixture more homogeneous. After the mixing process, the samples were dried for 48 h to remove the alcohol contained. The green body was made using the uniaxial pressing method at a pressure of 100 MPa and held for 3 minutes. The sintering process is carried out variously at temperatures of 800°C, 900°C, 1000°C, 1100°C, 1200°C, 1300°C, and 1400°C. with a heating rate of 5ºC/minute and holding time of 4 h. Next, the temperature was lowered to 300ºC with a cooling rate of 5ºC/minute. The results showed that linear shrinkage increased significantly (weight shrinkage increased 12.83% - 25.08% and diameter shrinkage increased 3.26% - 23.21%). The results of the relative density calculation show that there is a significant increase with each variation in sintering temperature, where the increase occurs from 44.4% - 85.6%. The compressive strength value also shows an increase with increasing sintering temperature, namely from 21.2 MPa at 800 oC to 65.9 MPa at 1300 oC. Meanwhile, at a sintering temperature of 1400°C, compressive strength values decreased and oxidation occurred as evidenced by color changes. It can be concluded that the optimization of the sintering process occurs at a temperature of 1300 oC which is proven by the highest compressive strength value and no oxidation occurs.

Recycled Surgical Mask Waste as a Resource Material in Sustainable Geopolymer Bricks

With the advent of the COVID-19 pandemic, the global consumption of single-use surgical masks has risen immensely, and it is expected to grow in the coming years. Simultaneously, the disposal of surgical masks in the environment has caused plastic pollution, and therefore, it is exigent to find innovative ways to handle this problem. In this study, surgical masks were processed in a laboratory using the mechanical grinding method to obtain recycled surgical masks (RSM). The RSM was added in doses of 0%, 1%, 2%, 3%, and 4% by volume of geopolymer bricks, which were synthesized with ground granulated blast furnace slag (GGBS), rice husk ash (RHA), sand, and sodium silicate (Na2SiO3) at ambient conditions for a duration of 28 days. The developed bricks were tested for compressive strength, flexural strength, density, water absorption, efflorescence, and drying shrinkage. The results of the study reveal that compressive strength and flexural strength improved with the inclusion of RSM in the bricks. The highest values of compressive strength and flexural strength were 5.97 MPa and 1.62 MPa for bricks with 4% RSM, respectively. Further, a reduction in the self-weight of the bricks was noticed with an increase in RSM. There was no pronounced effect of RSM on the water absorption and efflorescence properties. However, the RSM played a role in reducing the drying shrinkage of the bricks. The sustainability analysis divulges the catalytic role of RSM in improving material performance, thereby proving to be a potential candidate for low-carbon material in the construction industry.

Preparation and reaction mechanism of low environmental load mud solidification agent from multivariate solid waste

Utilizing various industrial solid waste to replace cement to prepare mud solidification materials could achieve energy conservation, carbon reduction and sustainable development. This research conducted solidification mud (SM) experiments using solidification agent (SA) compounded by mixing five types of solid waste. The focus was on studying the performance of SA and SM in the presence of different activators, as well as the influence of different activators on the SA curing mechanism. The results indicate that the SA and SM specimens with 3.0% Na2SiO3 addition had the highest compressive strength values at 1 d and 28 d, respectively. In addition, the microscopic test analysis showed that when 3.0% Na2SiO3 was added, the hydration activity of SA was relatively high, and the continuous distribution of cluster gel in the hydration product made its overall structure more compact.

A Study of Physical and Mechanical Properties using Kenaf Core as Coarse Aggregate Replacement in Concrete

Kenaf is well known for its one of the highest rankings of biomass producers compared to other fibre crops which excessive amounts of biomass could lead to contamination of soil due to its pollutants elements. Not only that, the high demand for aggregate for concrete production requires massive use of natural stone materials which leads to the destruction of the ecological balance of the environment. As in Malaysia, kenaf core is commonly used and available in abundance after the processing of kenaf stems for bast fiber production. Thus, this research aims to determine the physical and mechanical properties of kenaf core as fine aggregate replacement in concrete. There were 45 samples of the concrete cube of 100 mm x 100 mm with the percentage used of 0, 5, 15 and 25 % kenaf core replacement. A density test was conducted as well as a compressive strength test to obtain the objectives of the study. Findings reveal that the control sample still has the highest value of compressive strength of 34.7 MPa while 5 % of kenaf core concrete shows 28.50 MPa which slight decrease in the value in comparison. The value then gradually decreases as the percentage of the kenaf core increases. The density test also reveals that 25 % kenaf core shows the lowest value of density by 1419.78 kg/m3 compared to normal concrete. Thus, this indicates that the optimum percentage of kenaf core used was 5 % even though it still did not surpass 0 % concrete.

THE UTILIZING OF RECYCLED PLASTIC WASTE AS AN ALTERNATIVE FOR ZERO CEMENT PAVING BLOCKS

The problem of plastic waste that needs to be handled and managed optimally can cause environmental damage. This study aims to test the compressive strength and water absorption value of paving blocks made of plastic which are designed using a mixed variation of V50-50 (50% sand, 50% plastic), V25-75 (25% sand, 75% plastic) and V0-100 (0% sand, 100% plastic) of the total proportion of the paving blocks mix. The method is carried out by melting PP (Polypropylene) mineral glass plastic, mixing with sand based on variations, printing according to the size of the paving block, and using as a test sample in the form of a dice. The average compressive strength test results show that the model with code V25-75 has a relatively higher compressive strength value than V50-50 and V0-100. The average compressive strength value of the sample with code V25-75 is 11.53 MPa, followed by code V50-50 of 9.63 MPa, and the lowest is coded V0-100 of 3.70 MPa. The compressive strength value is influenced by the optimal percentage between sand and plastic; plastic serves as a binder for sand in a mixture of paving blocks. The rate of water absorption value will continue to decrease along with the addition of plastic waste in the paving block mixture; V50-50 is 1.44, V25-75 is 0.88, and V0-100 is 0.16. This research is expected to be applied by the community to make paving block products to reduce the amount of plastic waste globally.

Strength Properties of Polymer Reactive Powder Concrete with Waste Materials

Reactive powder concrete, or RPC, outperforms conventional or even high-performance concrete in terms of ultra-high strength and better durability. Several buildings were destroyed in Iraq, and recycling the garbage from these buildings can significantly help reduce waste and environmental pollution as well as serve as a source of aggregate for use in new construction. Reusing garbage and using sustainable building materials are now crucial environmental challenges, so this study aimed to replace the natural fine aggregate, NFA, used in preparations of polymer reactive powder concreter, "PRPC" with recycled aggregates, or RA, from crushed old concrete, COC, in order to make PRPC production more environmentally and sustainably friendly. In this study, RPC is modified by adding styrene butadiene rubber (SBR), a polymer, to the original mixture at a ratio of 13% by weight of cement. This study sought to determine the effect of using COC as recycled fine aggregate (RFA) on the compressive, splitting, and flexural strengths of PRPC. The main objective of this investigation is to study the effect of oil (water, new oil, and waste engine oil) on the compressive and tensile strengths of PRPC with COC and to compare the behavior with that of a control mix (PRPC with NFA). The mixtures were prepared using six different percentages of RFA, replacing 0, 20, 40, 60, 80, and 100% NfA. After 28 days, the six mixes were divided into three groups. The first was still being cured in water, W; the second in waste engine oil, WEO; and the third in kerosene oil, KO. The results showed that using COC as RFA in PRPC was viable, and according to this investigation, the mix with 40% COC replacement with NFA provides the highest values of compressive strength, tensile strength, and flexural strength before and after exposure to liquids (water, new oil, and waste engine oil). Doi: 10.28991/CEJ-2023-09-08-09 Full Text: PDF

Pemanfaatan Serat Ampas Tebu Sebagai Bahan Tambah Dalam Campuran Beton

Concrete is a construction material that is often used in building construction. Concrete is a mixture consisting of coarse aggregate and fine aggregate mixed with water and cement as a binder and filler, and additives are often added. Bagasse fiber has the criteria needed to be used as an added material for strengthening concrete. The variations of bagasse fiber used were 0%, 2.5%, 5%, 7.5% and 10%. The results showed a decrease in the slump value, this was due to the higher variation of bagasse substituted for the weight of cement with the same FAS value, which would reduce the workability of the concrete. The compressive strength of concrete with variations of sugarcane fiber decreased. The highest compressive strength value is found at 0% variation, namely 20.93 MPa, this is due to the greater percentage of bagasse fiber mixture, the concrete that should be filled with aggregate is filled with sugarcane fiber, causing the compressive strength of the concrete to decrease.

Analysis of the properties of chemically bound phosphate ceramics (CBPCs) produced from metakaolin with various acid phosphates

In this study, chemically bound phosphate ceramics (CBPCs), a type of geopolymer, were synthesized by reacting metakaolin (MK) with acidic solutions of phosphoric acid (PA), potassium dihydrogen phosphate (KDP), calcium dihydrogen phosphate (CDP), and aluminum dihydrogen phosphate (ADP). The obtained CBPCs were characterized using thermal analysis (DTA-TG), X-ray diffraction, dilatometry, and scanning electron microscopy and by their real density, porosity, water absorption, and compressive strength. The analyses revealed that the used acid phosphate type strongly influenced the properties of the resulting CBPCs. The best compressive strength results were found in CBPCs obtained using ADP, with an average value of 34.50 MPa and average porosity of 23.21%. For CBPCs obtained from PA, CDP, and KDP, the average compressive strength values were 14.18, 8.17, and 2.84 MPa, respectively; their average porosities were 18.79%, 36.23%, and 37.90%, respectively. The results demonstrate that CBPCs produced with MK can be cured at room temperature and that CBPCs obtained with ADP have higher compressive strength values than these of the other acids.

Compressive strength and fire resistance of mortar containing crushed cockle shell as fine aggregate replacement

Continuous extraction of sand from the river without any control would disrupt the ecosystem in the river. In addition, disposal of cockle shells as garbage contributes to pollution and an unpleasant atmosphere. Thus, the current study investigates the influence of substitution of crushed cockle shell as a partial fine aggregate on the compressive strength and fire resistance of mortar.Five mortar mixes were created by using 0%, 10%, 20%, 30%, and 40% crushed cockle shell replacement by weight of sand. Compressive strength and fire resistance tests were carried out. The results demonstrate that using 10% crushed cockle shell produces mortar with the highest compressive strength value. All mixes met the target strength at 28 days, with values ranging from 17.52 MPa to 22.21 MPa. Up to 600 °C, the mortar containing 10% crushed cockle shell exhibits more mass and strength loss almost compared to control mortar. Excessive use of crushed cockle shell results in greatest mass loss and strength when exposed to high temperatures. On overall, the incorporation of cockle shell substitute as fine aggregate would reduce the demand for natural river sand and pollution caused by cockle shell disposal.