Fibers Research Papers - Academia.edu (original) (raw)

High performance lightweight foamed concrete has the same mechanical properties of normal weight concrete (conventional concrete). The main applications are void filling, bridge abutments, bridge decks, marine structures, frame buildings, roads, sewer systems, roofing, walls, and floors. However, concrete is extensive brittleness and considered weak material in tension. Glass fibers are used as additive to the lightweight foamed concrete to increase the energy absorption capacity. The work was prepared to investigate the effect of glass fibers on tensile properties of lightweight foamed concrete with different volume fraction of glass fibers (0.06, 0.2, 0.4 and 0.6%) by the testing fresh density, dry density, flowability, compressive strength, direct tensile strength and splitting tensile strength. The results showed that a reduction in flowability was obtained with increased glass fibers content. Besides, the fresh and dry densities increased with the addition of glass fibers. Also, significant enhancements in compressive strength, direct tensile strength and splitting tensile strength were got by glass fibers inclusion. Thus, the increase of compressive strength, direct tensile strength and splitting tensile strength were up to the 56.6%, 50% and 46%, respectively, due to 0.6% glass fibers. 1. Introduction Aerated concrete is known as lightweight foamed concrete (LWFC). LWFC is lighter than normal weight concrete by mixing foams into cement slurry, LWFC has been a very recognized material with its noticeable characteristics particularly in thermal insulation with a low thermal conductivity between 0.10 W/mK to 0.66 W/mK [1,2]. Density of foam concrete about (400 to 1600 kg/m 3) depending on proportion of foam agent and water, foam concrete can be using for structural application, partition, insulation and filling grades [2]. The structural lightweight concrete having bulk density lower than 1950 Kg/m 3 and compressive strength more than 17 MPa. The structural lightweight concrete is 25% lighter than normal-weight concrete with a compressive strength up to 60 MPa [3]. The main reason of using lightweight concrete for structural purposes is to reduce the self-weight of concrete structures. Reducing the dead load of the structure is very important in earthquake regions, for tall buildings, and special concrete structures [4]. The Concrete is substantial brittleness, and which results in poor fracture toughness, poor resistance to crack propagation, and low impact strength. This inherent brittleness has limited their application in fields requiring high impact, vibration and fracture strengths. Concrete with fibers have wide range of usage due to their obvious advantages over ordinary concrete. The function of the use fibers in concrete to enhance the mechanical properties of concrete. Fibers are used to modify the tensile and flexural strengths, toughness, impact resistance, fracture energy, arrest crack formation and propagation, and thus improve strength and ductility. The concrete with fiber as additive are used widely in highways, tunnel linings, concrete pipes, reinforced concrete frames, reinforced concrete beam members, shell roof systems, skyscrapers and pre-stressed concrete, light shell constructions, domes and folded plates in recent years [5-9]. (Ghorpade, 2010) [10] investigated the effect of glass fiber on high performance concrete with silica fume as admixture. The length of fiber is 12mm and the specific gravity of the fiber is 2.68. Glass fibers by 0, 0.5, 1.0, and 1.5 % to produce high performance concrete. The maximum percentage increase in compressive strength is observed at 1% fiber and 10% silica fume. The flexural strength is increased up to 1% of fiber volume then the strength is decreased. It is also observed that the use of glass fiber up to 1.0% percentage increases the splitting tensile strength. (Murthy et al., 2012) [11] studied the performance of glass fiber reinforced concrete. The results shows the increase in compressive strength is nominal while the flexural strength increased significantly as expected with the increase in percentage of glass fiber. Also, significant reduction in the slump value of the glass fiber reinforced concrete was observed with increase in glass fiber content. (Chandramouli et al., 2010) [12] founded the addition of glass fibers to concrete enhance the mechanical properties of the concrete. Significance improved in the compressive strength, flexural strength and splitting tensile strength due addition 0.03% glass fibers.