Investigation of the mechanical properties of concrete containing recycled aggregate and scrap crumb rubber and polypropylene fibers

Abstract

In this study, the effect of using crumb rubber and recycled aggregates on the mechanical properties of concrete has been evaluated as areplacement of fine and coarse aggregates In order to add the admixtures and evaluate their combined effect, 20 different types of concrete mixture ratio were prepared. The results indicated that in those samples containing crumb rubber and recycled aggregates the compressive strength is reduced and adding fiber up to 0.1%. to these concrete samples can improve the compressive strength Also, the tensile strength of the samples mixed with crumb rubber and recycled aggregates were decreased, and with the addition of propylene fiber up to 0.4%. the tensile strength slightly increased Moreover by adding the crumb rubber to the samples the elasticity modulus was reduced but by adding fiber to samples about 0.1% and 0.2.% the modulus of elasticity of concrete in all samples were increased. According to the results, it can be said that using the combination of 5% of crumb rubber as a replacement of fine aggregate, and the combination of 35% of recycled aggregates as a replacement of coarse aggregate, and also by adding 0.1% polypropylene fiber in volumetric percentage of concrete along with adding 7% of micro silica as a replacement of cement led to the best effect on the mechanical properties of concrete.

Experimental assessment and compressive constitutive model of rubberized concrete confined by steel tube

“…A high-performance water-reducer agent used is Q8011 polycarboxylic acid-based (standard type) water reducer produced by QinFen Building Materials Factory, with a water reduction rate of 26%, as shown in Figure 2(a). Rubber aggregate used in the experiment is 40mesh rubber powder with an apparent density of 1.05 g/cm 3 produced by Sichuan Sito Rubber Co., Ltd, as shown in Figure 2(b). The sand is ordinary river sand, with an apparent density of 2.793 g/ cm 3 determined by the drainage method and a fineness modulus of 2.43.…”

“…Rubber aggregate used in the experiment is 40mesh rubber powder with an apparent density of 1.05 g/cm 3 produced by Sichuan Sito Rubber Co., Ltd, as shown in Figure 2(b). The sand is ordinary river sand, with an apparent density of 2.793 g/ cm 3 determined by the drainage method and a fineness modulus of 2.43. Rubber powder was added to replace part of the fine aggregate by equal volume ratio.…”

“…The addition of rubber aggregate reduces the brittleness of concrete, improves its ductility, and reduces crack formation. 3 Compared with conventional cement-based concrete, RuC has superior performance in terms of elasticity, impact resistance, heat insulation, noise reduction, and durability. 4,5 However, the partial replacement of fine or coarse aggregates with crumb rubber has been found to reduce the compressive strength and elastic modulus of RuC.…”

Ultra-High-Performance Alkali-Activated Concrete: Effect of Waste Crumb Rubber Aggregate Proportions on Tensile and Flexural Properties

“…Although higher rubber content could lead a reduction in the mechanical performance of concrete, the negative effects can be mitigated by judiciously adding steel fibres and silica fume, which have a positive influence on its microscopic interface [23][24][25][26]. Zahid and Moein [27,28], in their study on the mechanical properties of recycled aggregate concrete containing crumb rubber, found that flexural strength decreased with CR content increases, with a combination of 5% CR and 2% volume of fibres yielding the highest toughness and ductility. Shahjalal, et al [29] observed that a mixture of 5% CR and fibres enhanced energy absorption capability, when toughness and ductility gradually decreased with increasing CR content.…”

Examination of the permeability of rubberized concrete with different water/cement ratios and their resistance against acid and sulfate attack

“…7,8 Today, the aim is to evaluate recycled rubber particles in concrete, with many studies aimed at developing rubberized concrete. [9][10][11][12][13] These rubber particles are used in three classes: chips, crumbs, and powder rubber. 14 Waste rubbers can be commercialized and used in asphalt, plaster, mortar, and concrete.…”