20 research outputs found
Deformation Characteristics Of Malaysian Fired Clay-Bricks For Masonry Structures.
Penyelidikan ini melibatkan kajian berkaitan kekuatan mampatan bagi struktur dinding bata yang merupakan faktor penting yang mempengaruhi struktur dinding bata terutamanya untuk strulilur dinding yang menangggullg beban
Influence of Opening and Boundary Conditions on the Behavior of Concrete Hollow Block Walls: Experimental Results
The assembled pattern of concrete hollow building blocks contributes to the wall structure’s durability. This paper presents experimental research on the behavior of concrete hollow block walls. The experimental work included testing four concrete hollow block wall panels with different opening sizes. Constant vertical axial load was applied on top of the wall panels until failure, characterized by boundary conditions. The results showed that the presence of openings reduced the strength of the wall panels; it was possible to observe these differences since the opening area was between 20 and 40% of the gross wall panel area. It was also observed that while the opening percentage had a significant impact on the strength of the wall, the boundary conditions had a less substantial impact on the overall wall response. A high localized concentration of stress was observed at the top corners of the wall panels and a high stress concentration was also observed along the vertical sides of the openings. Variation in the number and the shape of the openings often changed the failure mechanism in the wall panels, even when the percentage area of the opening remained constant. The wall panels A1-B2 reached peak stress levels at 0.019 MPa, 0.036 MPa, 0.056 MPa, and 0.030 MPa. The equivalent peak strains were 0.018, 0.011, 0.012, and 0.010 respectively. This research established significant data and is expected to help in the design and analysis of axially loaded unreinforced masonry walls with openings
Evaluation of Acacia Mangium in Structural Size at Green Condition
Acacia mangium is one of the most popular choices in the reforestation and rehabilitation of abandoned shifting cultivation areas dated back to the 70’s. This paper looks into the evaluation of mechanical strength and physical properties in structural size at green condition for Acacia mangium. The mechanical strength properties tests were referred to the modulus of rupture, modulus of elasticity and tensile strength. Meanwhile, physical properties determination referred to basic density and moisture content. At green condition, Acacia mangium had been identified under the strength group SG6. It was found that strength value of modulus of rupture was higher than the
tensile strength value with 44% stronger in bending compared to in tension. At the structural size, the mean value for moisture content and basic density at green condition were reported with 73.03% and 0.54g/cm3 respectively
The Behavior of Strength Properties from Three Different Tree Boles of Aras in Sarawak
Aras had been selected and tested in small clear specimens. Sampling of test specimens are made from three sections of the tree bole namely from bottom, middle, and top parts. This paper looks into the information of strength properties from three sections of sampled. The strength properties test required are the modulus of rupture, modulus of elasticity and compression stress parallel to grain. Meanwhile, the physical properties' test referred to moisture content and basic density. The testing conducted in two different conditions of the trees, which were referred to green and air-dry condition. It was found that the average mean values for modulus of rupture, modulus of elasticity and compressive stress parallel to grain tested at green condition were 47.52N/mm2, 6358.56N/mm2 and 22.42N/mm2 respectively meanwhile at air-dry condition were 70.49N/mm2, 8217.64N/mm2 and 34.07N/mm2 respectively. Meanwhile, the average mean values for moisture content at green condition were 83.34% whilst at the air-dry condition were 12.33%. Basic density remains unchanged from both conditions
The Behavior of Strength Properties from Three Different Tree Boles of Aras in Sarawak
Aras had been selected and tested in small clear specimens. Sampling of test specimens are made from three sections of the tree bole namely from bottom, middle, and top parts. This paper looks into the information of strength properties from three sections of sampled. The strength properties test required are the modulus of rupture, modulus of elasticity and compression stress parallel to grain. Meanwhile, the physical properties' test referred to moisture content and basic density. The testing conducted in two different conditions of the trees, which were referred to green and air-dry condition. It was found that the average mean values for modulus of rupture, modulus of elasticity and compressive stress parallel to grain tested at green condition were 47.52N/mm2, 6358.56N/mm2 and 22.42N/mm2 respectively meanwhile at air-dry condition were 70.49N/mm2, 8217.64N/mm2 and 34.07N/mm2 respectively. Meanwhile, the average mean values for moisture content at green condition were 83.34% whilst at the air-dry condition were 12.33%. Basic density remains unchanged from both conditions
Investigation on the mechanical properties of rubberized steel fiber concrete
Researchers investigated the utilization of crumb rubber aggregate recycled from waste tire in concrete to solve the problem of discarded tire and to produce a green sustainable concrete. However, a reduction in the mechanical properties due to crumb rubber inclusion occurs. Steel fiber rubberized concrete used in this study to provide a balance between the strength loss and sustainable issue. An investigation on the mechanical properties of rubberized concrete combined with hooked – end steel fiber is presented. Rubberized concrete with different replacement ratios of crumb rubber was incorporated in plain and steel fiber concrete mixes via partial replacement of fine aggregate. Four replacement ratios (17.5%, 20%, 22.5%, and 25%) were used to investigate the effect of the partial replacement of fine aggregate by crumb rubber on the mechanical properties of plain and steel fiber concrete. In both mixes, reduction in mechanical properties was observed to be proportionate with the increment of crumb rubber. Finally, a successful combination of steel fiber and crumb rubber was obtained due to improvement of strain capacity under flexural loading
Basic and Grade Stress for Some Timber in Sarawak
Strength properties’ tests are conducted in the small clear sample. This paper aim to acquire the basic and grade stresses of some fast growing species thus identifies its strength group. Thus, the information of wood properties from different species and condition are acquired from strength property's test. The required information namely, bending parallel to the grain, compression stress parallel to grain, shear parallel to grain and modulus of elasticity. The condition of the trees which is referred to green and air-dry condition. Three different species which are referred to exotic species of Acacia mangium and indigenous species of Aras. The results from the study indicated that, Acacia mangium classified under the strength group SG5, whilst Aras was classified under the strength group SG7. The timber is of medium density Light Harwood ranging from 0.37-0.52g/cm3 air-dry condition
Cumulative Effect of Crumb Rubber and Steel Fiber on the Flexural Toughness of Concrete
Concrete properties, such as toughness and ductility,
are enhanced to resist different impacts or blast loads.
Rubberized concrete, which could be considered a green
material, is produced from recycled waste tires grinded into
different crumb rubber particle sizes and mixed with concrete. In
this study, the behavior of rubberized steel fiber-reinforced
concrete is investigated. Flexural performance of concrete beams
(40
Durability and mechanical properties of cement concrete comprising pozzolanic materials with alkali-activated binder : A comprehensive review
The disintegration of concrete structures made of ordinary Portland cement (OPC) is a worrying topic of increasing significance. The trend for reusing waste products or industrial by-products to reduce the amount of OPC in concrete constructions has become an important task for industries and research institutions. Although OPC is an essential ingredient for concrete and is immensely popular, it greatly contributes to the release of a massive quantity of CO2 into the atmosphere. To decrease the increasing CO2 emission, scholars and researchers in the construction industry and academic institutions have exerted efforts to adopt alternative sustainable binders using pozzolanic materials, such as metakaolin, fly ash, slag, rice husk ash, and palm oil fuel ash, combined with alkali-activator (AA). Many researchers have stated that AA alumina-silicate (Al2SiO2) materials can produce convincing mechanical and durability properties, such as compressive strength, splitting tensile strength, and modulus of elasticity, in cement concrete at an early age with low CO2 emission and energy consumption. Most researchers have reported that concrete containing pozzolanic materials and alkali-activated binder (AAB) has better durability than conventional concrete, while others call for further studies. According to previous studies, this research assesses the present studies on the mechanical and durability properties of cement concrete produced from the AAB related to the pozzolanic materials. Furthermore, few possible studies have been recommended in the future