Compressive Strength Test Results Research Articles

Effect of incorporating multifilament polypropylene fibers into alkaline activated fly ash soil mixtures

Soil stabilization is a well-known methods for the treatment problematic soils. Its advantages over soil replacement include low cost and fast implementation. The alkaline activation of soft soils is a new technique that has been proposed recently to stabilize soft soils. However, its strengthening mechanism and the final product in terms of stiffness and brittleness resemble those observed in cemented soils. In other words, the residual strength which emerges when approaching failure is very low, and this results in immediate damage to building structures. These shortcomings need to be overcome, particularly in places where seismic loading can be expected. In the case of cemented columns under heavy embankments, horizontal displacement is likely to occur under seismic loading. This will result in the failure of stabilized material due to frail bending moments, making greater residual strengths more important than higher peak strengths. To address this problem, a fix fly ash content of 40% and polypropylene fibers in the range of 0.5%, 0.75%, 1%, and 1.25% were considered. Compressive, flexural and indirect tensile strength test results revealed the feasibility of polypropylene fibers to improve post-peak behavior, thus allowing for higher residual strength after failure.

Utilization of waste rubber fiber considering modification in strength reduction factor and its effect on the behavior of concrete

Abstract In this Study, the improvisation on mix design and the analysis of the strength of rubberized concrete is carried out. The carbon fiber is cut in the prescribed ratio and used for the partial replacement of coarse aggregates. The carbon fibers were mixed with the concrete to form a Rubberized concrete. To obtain a rubberized concrete mixture, all mix design parameters were kept constant as given by the IS-456 method except for the coarse aggregate constituents. The coarse aggregate of the concrete was replaced by 5%, 10%, 15%, 20% and 25% of its weight. The fine aggregate was sieved using 2.36 mm in order to pass through the holes of the carbon fiber to make a strong contact with the cement matrix. From some experimental results of compressive strength testing it was observed that both plain and rubberized concrete developing similar strength over the curing period as expected. For all concrete mixtures, the rate of compressive strength developed was high between 7 and 14 days and slow between 14 and 28 days. Also, it was noted that irrespective of the curing period, there was a systematic reduction in compressive strength with increasing rubber content of the composite. Some experimental investigations observed that a high percentage of carbon fiber mixed cylinders took a longer time to crackdown because of the elastic nature of the fibers when bearing the loading. Moreover, it was observed that the above said rubberized concrete did not exhibit brittle failure under compression or split tension.

Behavior of unconfined and CFRP confined rubberized concrete

Abstract The use of rubberized concrete (RuC) is an effective environmental approach to reduce the amount of scrap tires around the world. However, there are serious concerns regarding the compressive strength of RuC. This article investigates the use of externally bonded carbon fiber reinforced polymer (CFRP) jackets on RuC to develop a novel high strength and deformable CFRP confined RuC. In this study, 66 RuC cylinders were cast with 0, 10, 20, 30, 40 and 50% fine or coarse rubber to replace mineral aggregates. The RuC cylinders were then confined with one, two or three layers of CFRP jackets. The results indicated 208% high lateral strains in unconfined RuC as compared to the conventional concrete. CFRP jacketing was highly effective for enhancing the compressive strength and deformation capacity of RuC, where high compressive strength enhancement of 52 MPa and deformation capacity (317% axial strain) was achieved. The confined compressive strength test results were compared with the strength models to assess their validity for CFRP confined RuC. An analysis-oriented strength model was developed to predict the axial compressive strength of RuC confined by CFRP jackets. Overall, this study demonstrated the potential of using CFRP-confined RuC as a new structural material with improved strength and deformation.

The effect of alkali activation solutions with different water glass/NaOH solution ratios on geopolymer composite materials

In this study, geopolymer materials were produced from fly ash (FA) supplied from İsken Sugözü Thermal Power Plant located in Adana, Turkey. FA and Rilem Cembureau Standard Sand were used together with the ratio of 0.50. At first, two different alkaline solution/material ratio (FA+standard sand) (L/M) were selected as 0.20 and 0.40 for the design parameters. In the production of geopolymer composite material, sodium silicate (Na2SiO3) and sodium hydroxide (12 M NaOH) were used together within the ratio of 1, 1.5, 2, 2.5 and 3 by weight, respectively. A totally of 20 mixes were cured at 70 and 100 oC for 24 hrs, respectively and thereafter kept in room temperature until testing age. Physical characteristics of hardened mortar were determined via the bulk density, water absorption and porosity values at 28 days while the strength of geopolymers was obtained on the results of compressive strength and flexural strength tests conducted at 7, 28 and 90 days. Considering the testing parameters, geopolymer material with the highest compressive strength was found as 76.0 MPa (28-days) on the mixture produced with L/M ratio of 20% by weight; the alkaline solution consisted of a mixture of Na2SiO3 and 12 M NaOH in weight ratio of 2 by curing at 70 oC for 24 hrs. However, test results showed that there was an optimum limit for the alkaline solution ratio, such that exceeding this limit gave the reverse effect for the strength characteristics of the geopolymer material.

Using of rice husk ash as material addition in mixing concrete by mixing 1 Cement : 2 Sand : 3G to increase the compressive strength

Concrete is a construction material with increased supply annually. Increased supply of concrete caused cement demand also increased while the price of cement also increased every year. Based on this case, some research was done by mixing additives that can improve concrete strength and reduce the amount of cement. One of the additives used is rice husk ash (RHA). However, the addition of RHA was not implemented in concrete with mixing by 1pc: 2ps: 3kr; while concrete mixing by 1pc:2ps:3kr are mostly used by local communities to construct multistory buildings in Pamekasan. Therefore, this study is done by adding the RHA of 0%, 3%, 5%, 7% and 9% of the weight of cement is added. Concrete compressive strength testing was performed on all types of samples on the concrete curing periods 7, 14, 21 and 28 days. Concrete compressive strength test results showed that the addition of 5% RHA is able to provide increased compressive strength of concrete is the most optimal compared to the percentage of the RHA. At the curing periods of 28 days of concrete with 5% RHA.

Modification of Engineering Properties of Clayey Soil by Addition of Mine Waste

The potential of using iron ore mine waste with an highly compressible clayey soil soil from North Karnataka, India, is investigated in this study. Mining activities lead to the production of waste materials during their extraction and processing stages. The waste maybe in the form of an overburden, waste Rock, Mine Water, or Tailings, depending on the geology, type of processing technology used and the resources mined. The lack of storage space has also been a major concern for the mineral producing agencies, thus paving ways for its better utilization in various construction processes. The collected mine waste was added to expansive soil in different percentages and the mix was tested for Atterberg limits, compaction characteristics, Unconfined compressive strength and California bearing Ratio. It was found that the liquid limit and plasticity index of the soil reduced with addition of mine waste while strength improved. Based on test results of maximum dry density and unconfined compressive strength, a mix of 40% mine waste with 60% expansive clayey soil is recommended for low cost roads. Blending mine waste with expansive soil paves way for sustainable construction besides economic benefits

Evaluation of Fiber Type and Water-Binder Ratio Influence on Concrete Properties

This paper enumerates the experimental study on workability and strength properties of concrete containing different dosage of polypropylene fiber from 0.1% to 0.6% and 1.0% to 3.5% of steel fiber. Water – binder ratio, fiber type and fiber dosage influence on flow behaviour, compressive strength, flexural strength and brittleness ratio were analysed. Experimental results were substantiated by linear regression analysis considering 95% confidence level. Reference mixes with 0.34 and 0.36 water- binder were prepared for results comparison with polypropylene and steel fiber reinforced concretes. Test results showed comparatively higher workability reduction in polypropylene fiber reinforced concrete. Compressive strength test results of fiber reinforced concrete indicted an optimum fiber content of 0.30% of polypropylene fiber and 2.50% of steel fiber. Steel fiber reinforced concrete displayed continuous increase in flexural strength with 44.46% average increase. Brittleness ratio, which was the ratio of flexural strength and compressive strength showed maximum value of 0.24 for concrete with 3.5 % steel fiber and 0.36 w/B ratio. Linear regression analysis revealed good correlation of flow properties with w/B ratio irrespective of fiber type. Though the compressive strength had low correlation with fiber type and w/B ratio, steel fiber reinforced concrete indicated up to 0.987 coefficient of determination with flexural strength.

Analysis of Compression Strength on Plastic Brick Material

Plastic waste has a negative impact on the environment, handling plastic waste by utilizing plastic waste and sand to make plastic bricks. This study aims to make plastic bricks, test the compressive strength of plastic bricks and determine the density. Making plastic stones using the experimental method, this method of experimenting with experience to prove themselves a statement that is learned. Maximum compressive strength test results in samples 1, 1 kg of plastic: 1 kg of sand = 141.42 kg/cm2. Sample 2, 1.15 kg plastic: 0.85 kg sand = 117.23 kg / cm2 and Sample 3, 0.85 kg plastic: 1.15 kg sand = 112.50 kg / cm2. Average mass weight sample 1 (1.25 kg) and the average lost weight of sample 1 (0.75 kg), average weight mass of sample 2 (1.39 kg) and lost average sample weight 2 (0.61 kg), mass average weight of sample 3 (1.3 kg) and loss of average sample weight 3 (0.7 kg) with total material used 2 kg. Based on the results of compressive strength tests, plastic bricks meet quality standards (SNI 15-2-94-1991). Thus this research can replace industrial products and maintain a healthy environment.

Study on carbonation process of β-C2S under microbial enzymatic action

Bacteria can accelerate the carbonation process occurring in freshly cast specimens; thereby, improve the mechanical and durability properties of steel slag products. β-C2S is one of the main mineral phases in steel slag. For simplification, the β-C2S was utilized to study the mechanisms of hydration process of steel slag. This paper focused on the influence of bacteria on formation of hydration products and development of compressive strength of steel slag products. The microstructure of the carbonized β-C2S specimens was also studied. By analyzing the results of compressive strength, QXRD, SEM-EDS, X-CT, BET and MIP tests, it could be found that the addition of bacteria has increased the degree of carbonation by 16.1% and the compressive strength by 30.1%. It did not change the form of calcium carbonate crystal but had great effects on the morphology and the size of the crystals, which might account for the improved carbonation and hydration degree of steel slag products. The pore structure of β-C2S specimens was refined with the incorporation of bacteria.

PENGARUH PENGGUNAAN LIMBAH PLASTIK POLYPROPYLENE (PP) SEBAGAI CAMPURAN AGREGAT KASAR TERHADAP KUAT TEKAN DAN TARIK PADA BETON FC’ 25 MPA

Indonesia ranks second in the world's largest plastic waste producer after China. Each year, Indonesia can contributeup to 187.2 million tons of plastic waste, while China reaches 262.9 million tons of plastic waste. Based on the data, one way to utilize plastic waste by using plastic waste as a mixture of concrete, where the plastic used is polypropylene (PP) plastic with different percentage of concrete mixture, the test includes compressive strength test and tensile concrete. The results of concrete compressive strength testing with polypropylene (PP) plastic waste mixture of 5%, 10% and 15% at age 28 in aggregate aggregate mixture decreased by 5.15%, 6.89% and 13.53%. As for the result of concrete tensile strength test with polypropylene (PP) plastic waste mixture of 5%, 10% and 15% at age 28 in crude aggregate mixture decreased 17,61%, 24,13% dan 23,24%.

Experimental Study of Mortar Compressive Strength with Anadara Granosa Powder as a Substitute for Partial Use of Cement

Making cement produces carbon dioxide (CO2) gas which results in the greenhouse effect. To reduce the use of cement, alternative materials are examined. One of the raw materials for making cement is limestone. Limestone is a sedimentary rock mainly composed of calcium carbonate. Blood clams (Anadara Granosa) are tried to replace cement because they have a high calcium carbonate mineral composition. Blood clams are crushed into powder and filtered using No.325 filter. Cement is replaced by weight by 5%, 10%, 15%, and 20%. Mortar specimens in the form of cubes with a size of 5 cm. Mortar compressive strength test was carried out at 7 and 28 days. Anadara Granosa powder reacts very weakly with water and increases the initial compressive strength of the mortar. The results of Anadara Granosa mortar compressive strength test at 7 days were higher than normal mortar. The most efficient composition is indicated by cement replacement of 20%.

Impact of Incorporating Metakaolin on the Mechanical Performance of High Grade Concrete

This paper studies the effect of incorporating metakaolin on the mechanical properties of high grade concrete. Three different metakaolins calcined at different temperature and durations were used to make concrete specimens. Three different concrete mixtures were characterized using 20% metakaolin in place of cement. A normal concrete mix was also made for comparison purpose. The compressive strength test, split tensile test and flexural strength tests were conducted on the specimens. The compressive strength test results showed that all the metakaolin incorporated concrete specimens exhibited higher compressive strength and performed better than normal concrete at all the days of curing. The rate of strength development of all the mixes was also studied. The study revealed that all the three different metakaolin incorporated mixtures had different rate of strength development for all the days of hydration (3, 7,14, 28, 56 and 90), indicating that all the metakaolins possessed different rate of pozzolanic reactivity. Further, from the analysis of the test results, it was concluded that the variation in the rate of strength development is due to the differences in the temperature and duration at which they were manufactured. The results of split tensile strength test and the flexural strength test conducted on the specimens, supported the conclusions drawn from the results of compressive strength test. The paper also discusses, the rate of development of compressive strength and the pozzolanic behaviour of the metakaolins in light of their parameters of calcination and physical properties such as amorphousness and particle size. This paper has been written with a view to make the potential of metakaolin available to the construction industry at large.

Assessing the effect of freezing-thawing cycles on the results of the triaxial compressive strength test for calc-schist rock

Freezing-thawing (F-T) is an important mechanical weathering process in mountainous areas. Therefore, evaluating the effect of this phenomenon on rock properties is required for design in mining and rock engineering projects constructed in these areas. In this research, the influences of F-T cycles on triaxial compressive strength (TCS) test results were studied for calc-schist rock samples from the Angouran open-pit mine. For this purpose, 1200 m of drilling was performed in the mine in order to prepare the required specimens. About thirty calc-schist samples were tested at F-T cycles of 0, 7, 15, 40, and 75 and lateral stress of 0, 2, 4, 6, 8, and 10 MPa using the servo-control triaxial device. Each weathering cycle was conducted in 12 h of freezing and 12 h of thawing at −20 °C to 20C°, respectively. Changes occurred in texture and microstructures of samples after weathering process were analyzed using the scanning electronic microscope (SEM). The SEM results showed the increase in micro- and macro-cracks in the samples structures and disappearance of cement in their matrix. Also, the results of TCS tests showed an exponential decrease in cohesion and internal friction angle with increasing the number of F-T cycles. As another finding of this study is that increasing the number of F-T cycles leads to a decrease in TCS values. Finally, an empirical equation is developed between TCS and number of F-T cycles for Angouran mine calc-schist.

The Impact of Fly Ash after SNCR Treated with Tannin-Based Products on AAC Production

This paper is focused on the effect of treatment of fly ash after selective non-catalytic reduction (SNCR) with tannin on autoclaved aerated concrete (AAC) production in order to reduce or stop ammonia leakage from the fresh mixture due to its alkalinity. A pure form of tannin and a tannin-based product „Farmatan“ were used as a treatment in dosage ranging from 0,5 g – 3 g of agent per 1 kg of fly ash. Efficient dosage was determined at 2 wt.% of fly ash by the speed of an indicator change due to gaseous ammonia diluted in water. The rheological properties of fresh mixtures were observed by consistency test in Viskomat showing that Farmatan causes delay of hydration. The results of bulk density and compressive strength testing revealed that Farmatan causes an increase of bulk density and at higher amount decreases the compressive strength because of thermal crack formation due to combined effect of delayed hydration and thixotropy. Using x-ray diffraction (XRD) analysis there were no differences in phase composition observed.

Unsaturated behavior of rammed earth: Experimentation towards numerical modelling

This study concerns the coupled hydro-mechanical behavior of rammed earth, which is a real difficulty for the development of this construction technique. Unconfined compressive strength tests on samples conditioned at different relative humidities were performed to determine the variation of mechanical capacity with suction. Both compressive strength and Young’s modulus increase with suction. Further, the effect of shear characteristics with the hydric conditions was studied by direct shear test. As suction induced cohesion contributes a significant part of strength, the apparent cohesion reduced with the reduction of suction. In addition, a considerable variation was observed in the friction angle. Unconsolidated undrained triaxial tests on unsaturated samples were performed to plot the failure envelope for a greater value of normal stress and to complete the failure envelope. These three test makes it possible to put in evidence a non-linearity in the failure envelope over all the suction range studied. Consolidated undrained triaxial tests on saturated samples were performed to determine the intrinsic cohesion and intrinsic friction angle. It was observed that Mohr-Coulomb criterion is not realistic for rammed earth and the failure envelope is non-linear for unsaturated conditions. Thus, a failure criterion was proposed in which both cohesion and friction angle are dependent on normal stress applied. The expression for Bishop’s effective stress for unsaturated soil was evaluated from the results of triaxial and unconfined compressive strength test together. The non-linear failure criterion obtained for a particular suction can be extended to other suction states through Bishop’s effective stress formulation. It can further be used for coupled hydro-mechanical modeling of rammed earth structures.

Effect of foam glass granules fillers modification of lime-sand products on their microstructure

Abstract Silicate products are products made exclusively from natural raw materials. A relatively high value of the heat transfer coefficient is still considered a fault. This property adversely affects the thermal insulation of buildings and energy consumption, so you should look for materials with a low heat conduction coefficient. One of the ways of obtaining such products can be the use of light, porous fillers in the mass of lime-sand products. Due to the above, particular attention was paid to white foam glass in the form of granules, which is a product of recycling glass cullet. The research was carried out with a granulate size of 0.25-0.5 mm, share of which in the tested samples ranged from 5 to 30%. The obtained results were referred to the tests carried out on basic (lime-sand) sample. The aim of the article is to determine the correctness of the formation of selected usable properties of modified lime-sand products, taking into account changes in their microstructure. The article describes the results of volume density and compressive strength tests of basic samples and the samples modified by using the expanded glass granulate as well as the results of their observations by using of SEM and tests of phase composition obtained from XRD.

UJI KUALITAS BIOBRIKET CAMPURAN TEMPURUNG KELAPA, TONGKOL JAGUNG, DAN SEKAM PADI DENGAN TEPUNG SAGU SEBAGAI PERAKAT

Research has been carried out with the title of the biobriquette quality mixture of coconut shell, corn cobs, and rice husk with sago flour as adhesive. The purpose of this study was to determine the quality of the bio-briquettes with a mixture of coconut shells, corn cobs and rice husks with sago flour as an adhesive. In this study the raw material used was coconut shell with the process of drying at temperatures of 3500C, corn cobs with a temperature of 1500C and rice husks with a temperature of 1200C with the composition used was 60%: 20%: 20%, 60%: 25%: 15%, 60%: 30%: 10% and 60%: 35%: 5% then sieving particle size for all 40 mesh samples, mixing using 3 grams of sago flour as bio-briquette adhesive, then bio-briquette printing and drying is done. Furthermore testing of compressive strength, moisture content, ash content, calorific value and combustion time with the results of compressive strength testing using the tool. TA.XTPlus Texture Analyzer the best characteristics obtained in the composition 60%: 35%: 5% with a value of 9.82 kg /cm2, and the best characteristic moisture content was tested in the composition of 60%: 30%: 10% with a value of 4.59%. The quality produced from the biobriquette mixture of coconut shell, corn cobs, and rice husk with sago flour as adhesive can be categorized as good. This is seen from the testing of water content, ash content and calorific value that meets the Indonesian national standard and the burning time of 152.18 minutes, except for compressive strength testing that does not equal to the quality standards of Indonesia.

Performance assessment of geopolymer concrete with partial replacement of ferrochrome slag as coarse aggregate

The present research work aims to produce fly ash geopolymer concrete with ferrochrome slag as coarse aggregate. The experimental results of all the properties of ferrochrome slag based geopolymer concrete are compared to controlled geopolymer concrete and proved as most efficient, technically acceptable and environmentally compatible construction material. From compressive strength, flexural strength and split tensile test results, it is observed that ferrochrome slag based geopolymer concrete shows excellent performance than that of controlled geopolymer concrete. Further, scanning electron microscopy (SEM), Energy dispersive X-ray analysis (EDX), Fourier transformed infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses are performed to study the behavior of microstructure with effect of different conditions.

Interpretation of X-Ray Images to Investigate the Viability of Incorporating Poly(Ethylene-co-Vinyl Acetate) (EVA) Waste in Portland Cement

EVA (poly (ethylene-co-vinyl acetate)) is a copolymer widely used in the Brazilian footwear industry, where approximately 18% of the EVA remains as waste, principally after the cutting out of insoles. EVA wastes cannot be recycled or reused for the original purpose, but it may be possible to add them to Portland cement to produce concrete for non-structural applications in constructions. This work presents an analytical technique based on the interpretation of X-ray images to assess the spatial distributions of these wastes within concrete test specimens. Evaluation was made of the feasibility of using this technique to study the incorporation of the wastes. Test specimens of concrete were produced according to Brazilian technical standard ABNT-NBR 5738, using a sand/gravel/cement ratio of 3:2:1, where EVA replaced part of the gravel content (10, 20, 50, and 70% of the total gravel volume). Analysis of front projection X-ray images of the specimens showed that the waste was homogeneously incorporated throughout the entire material, as required for concrete. The results of compressive strength tests showed that for samples containing up to 20% of EVA waste, the compression resistance remained almost unchanged, while incorporation of 50 or 70% of waste led to decreases of up to 64% in the resistance.

A new formulation for lightweight oil well cement slurry using a natural pozzolan

Fluid loss during cementing operation in depleted reservoirs or in deep wells of reservoirs with low breakdown pressure is a major concern for maintaining well integrity. To overcome this problem, the weight of cement slurry is usually reduced. Although various slurry formulations have been proposed during the last decade, the cost and availability of required additives is still an important concern, especially when the oil price is low. The objective of this study is to make lightweight cement slurry with a density of 105 lb/ft 3 , using the combination of natural pozzolan and API class G cement. In this study, a new formulation based on the optimum amount of a natural pozzolan and other additives is proposed. Based on the results of 24-hour compressive strength test and free water volume, 30% replacement of cement powder with pozzolan was selected as an optimal amount. Addition of more pozzolan into the slurry reduces its pumpability even at room temperature. Bottom-hole condition was simulated by increasing the temperature to 150°F and chemical additives were used to maintain the rheological properties of this slurry. Fluid loss control agent, dispersant and retarder were used at optimum values 0.5, 0.08 and 0.05 (%bwoc), respectively. The compressive strength of the cement rock was monitored at 3, 7 and 30 days, reaching 3528 psi after 30 days. Cited as : Larki, O., Norouzi Apourvari, S., Schaffie, M., Farazmand, R. A new formulation for lightweight oil well cement slurry using a natural pozzolan. Advances in Geo-Energy Research, 2019, 3(3): 242-249, doi: 10.26804/ager.2019.03.02