Papers by Keyword: Splitting Tensile Strength

Abstract: This study presents preliminary investigations on the strength properties of concrete using addition of Alccofine. Concrete mixtures were prepared with varying percentages of Alccofine ranging from 0% to 20% and tested for compression strength and splitting tensile strength after 7, 14 & 28 days of curing. During the first week of curing (7 days), the concrete gains initial strength. Extending the curing period to 14 days allows for further hydration and strength development in the concrete. The 28-days of curing period is a critical milestone in concrete curing, as it represents the standard duration for assessing the concrete's compressive strength characteristics. The optimum percentage of Alccofine was arrived at15%. Exceeding the optimum percentage of Alccofine (20%) can lead to an adverse effect on strength due to potential issues like excessive pozzolanic reactions or changes in the concrete's microstructure. This information will help in determining the optimal proportion of Alccofine for achieving the desired strength and performance characteristics in the concrete mixtures.

Abstract: Bottom ash (BTA), a by-product of coal combustion in electric power plants, is commonly regarded as waste, presenting challenges in its management. Conversely, laterite, typically used in road construction, has become increasingly expensive due to its high quality. This study aims to investigate the mechanical properties of laterite replaced with BTA and cement. The replacement of BTA ranged from 10% to 50% of the dry weight of laterite, with cement contents of 1% and 3% of the dry weight of the laterite-BTA mixture. Experimental tests, including unconfined compressive strength (USC) and splitting tensile strength (STS), were conducted. The results indicate that replacing laterite with BTA and cement enhances strength by 2 to 8 times that of unstabilized laterite, with 20% BTA replacement yielding the highest strengths. This approach not only provides cost-effective road construction materials but also contributes to sustainable practices by conserving natural resources and reducing pollution.

Abstract: Testing of the properties of cement mortars for 3D printing has not been standardized yet. Manufacturers of dry mixes declares tensile strength and compressive strength, but these properties are determined on standard beams for cement mortars, and their values may differ from the material actually formed by the 3D printing method. Another factor affecting strength is the printing process itself, where different printing machines require different consistencies and therefore different amount of water. Last but not least, it is necessary to take into account the different properties of the printed material depending on the direction of testing. Presented article brings results of determination the compressive strength, flexural tensile strength, splitting tensile strength and uniaxial tensile strength of the cement mortar from 3D printing loaded in different directions in relation to the axis of the print and comparing them with the parameters determined on standard beams made of the same material. A commercially produced dry mixture was used. Rectangular object was printed. Before the actual printing and also the fresh mixture was taken from the print head directly into the molds for the production of standard beams 40×40×160 mm. The printed object and the beams were placed in a water environment after 24 hours and the properties were determined at the age of 28 days. Cubes with dimensions of 40×40×40 mm and beams of 40×40×160 mm were subsequently cut from the printed object. The results of the testing point to a relatively large variability of the strength characteristics not only according to the direction of the load forces, but also in different places of the printed object (samples were taken in the bottom part, in the middle and in top of the printed object). Strengths of the standard beams were significantly higher than strengths of samples cut out from 3D printed object.

Abstract: Aggregates constitute 60 – 80% of total concrete constituents. The characteristics of concrete may be affected by the sources from which the aggregate was obtained. The effects of granite sourced from four selected locations within Ogbomoso, Nigeria; on the fresh and hardened properties of concrete were investigated. The granites were obtained from: Asafa (8⁰ 4.68¹ N and 4⁰ 20.78¹ E), Ola-jesu (8⁰ 13.59¹ N and 4⁰ 10.1¹ E), Igbo-ile (8⁰ 4.68¹ N and 4⁰ 19.57¹ E) and Apasu (8⁰ 14.96¹ N and 4⁰ 10.05¹ E). Sieve analysis, specific gravity, moisture content, Aggregate Crushing Value (ACV) and Aggregate Impact Value (AIV) of the granites were determined. The aggregates were used to produce concrete of two different mix ratio-1:2:4 and 1:3:6. Slump and compaction factor tests were carried out on fresh concrete and compressive strength, splitting tensile strength and water absorption on hardened concrete. The results indicated that granite obtained from Asafa and Ola-jesu exhibited improved characteristics over those sourced from Igbo-ile and Apasu and are more suitable for use in producing high-quality concrete.

Abstract: Five engineered cementitious composite mixtures were adopted in this study with five different contents of 0, 0.5, 1.0, 1.5 and 2.0% of untreated low cost PVA fiber. Four different test specimens were prepared from the five mixtures to conduct several tests. Abrasion tests were conducted using 300 mm discs for six time steps each of 12 hours, while 100 mm cubes were used to evaluate the compressive strength. Cylinders with 100 mm diameter and 200 mm depth were adopted for splitting tensile strength, while four-point bending tests were conducted using small concrete beams with a span of 210 mm. The modulus of rupture was calculated from the tested beams, while the stiffness and elastic energy were calculated based on the load and deflection records of the beams. The tests showed that compressive strength did not affected noticeably by fiber inclusion, while all other mechanical quantities in addition to abrasion resistance exhibited significant improvement due to PVA fiber effect. The stiffness, splitting tensile strength, modulus of rupture and elastic energy exhibited maximum developments of 45, 134, 287 and 1181%, respectively, due fiber addition to the mixture. Quadratic formulas were found to be very accurate to correlate the relationship between abrasion depth in millimeters and each of splitting tensile strength, modulus of rupture and elastic energy, where R² values of these relations were between 96.7 and 99.5%.

Abstract: The main objective of this study is to investigate the mechanical properties of dredged sediments, which are considered as waste from the process of removing sediments from the bottom of a dam's reservoir. The dredged sediments with stabilization can to be reused as construction and building materials in civil engineering works. The mechanical tests included unconfined compressive strength (UCS) and splitting tensile strength (STS) to understand the behavior of the dredged sediments stabilized with ordinary portland cement (OPC) type I and fly ash (FA). The overall test results indicated that OPC type I and FA were effective in stabilizing the sampled dredged sediments from two dams in northern Thailand. The stabilization with 10% FA content was found to be most effective for improving mechanical properties of the stabilized samples.

Abstract: This paper presents the flexural and splitting tensile strength of high strength concrete (HSC) with diatomite micro particles (DMP) as a mineral additive. In order to have micro particles, the diatomite from Aceh Besar District was ground and sieved with sieve size of 250 mm. The particles were then calcined at the temperature of 600 °C for 5 hours. Four mixtures were designed with different DMP to binder ratio (DMP/b). The ratio was 0%, 5%, 10% and 15%, and the water to binder ratio was 0.3. Four beam specimens with a size of 10 cm × 10 cm × 40 cm and four cylinder-specimens with 10 cm diameter and 20 cm high were prepared for each mixture. Flexural and splitting tensile tests were conducted based on ASTM C78 and ASTM C496/496M. The maximum flexural strength was reached at DMP/b of 5% while the maximum splitting tensile strength was reached at DMP/b of 0%.

Abstract: This research aims to investigate the mechanical properties of engineered cementitious composites including compressive strength, splitting tensile strength, modulus of rupture, and load-deflection behavior. In addition, the abrasion test of concrete under water, which is recommended by ASTM C1138, was carried out and its results were compared with the splitting and modulus of rupture test results. Untreated low-cost polyvinyl fibers were used with different volume fractions of 0.5, 1.0, 1.5, and 2.0%. All tests were carried out at the standard age of 28 days. The experimental results showed that the use of 2% of low cost polyvinyl fibers with the engineered cementitious composites led to the increase of the splitting tensile strength and the modulus of rupture by 134% and 287%, respectively, compared to specimens incorporating no fibers. The results showed also that the deflection and the ultimate failure load increases as the fiber content increase.

Abstract: The environmental footprint of the construction industry in general must be reduced. The process of manufacturing cement involves the release of appreciable amounts of CO₂ into the atmosphere. This paper summarizes the findings of an experimental study aiming at assessing the splitting tensile strength of self-consolidating concrete (SCC) in which 90% of the cement was replaced with various amounts of the industrial by-products including silica fume, fly ash, and ground granulated blast furnace slag (GGBS). Due to the high replacement ratio of cement with recycled industrial by-products, the produced SCC is referred in this study as green concrete. The compressive strength ranged between 30 MPa and 50 MPa and was produced with water/cementitious material ratios of 0.33 and 0.36. The splitting tensile strength was determined and a correlation was developed using regression analysis between the splitting tensile strength and compressive strength.

Abstract: Sustainable self-consolidating concrete (SCC) is gaining popularity due to its contribution to reducing the environmental footprint of the construction industry. Sustainability of this type of concrete comes from the significant reduction in usage of ordinary cement and its replacement with reused minerals and industrial by-products such as fly ash, ground granulated blast furnace slag (GGBS), and silica fume. In this study, the correlation between the splitting tensile strength and flexural strength is investigated by studying published data in the literature. Splitting tensile strength is determined through a simple test and flexural strength is obtained from flexural beam test. A correlation between the two measures of tensile capacity is essential to determine the flexural design strength knowing the splitting tensile strength, especially for SCC. A correlation is proposed in this paper to relate flexural and splitting tensile strengths for concrete in which cement was replaced by sustainable minerals and industrial by-products.