Impact of Chemically Treated Waste Rubber Tire Aggregates on Mechanical, Durability and Thermal Properties of Concrete

Abstract

Studies have shown that the incorporation of waste tire rubber aggregates reduces the strength, increases permeability and decrease thermal conductivity of concrete. However, only a few studies have investigated the effect of surface-modified rubber aggregates on the properties of concrete. This study investigates the effect of the surface treatment of waste tire rubber as coarse aggregates with different oxidizing solutions and different treatment durations on the mechanical, durability and thermal properties of concrete. The properties of concrete incorporated with 8% rubber coarse aggregates (by volume of natural aggregates) which were treated with three different solutions: water (H 2 O), 20% sodium hydroxide (NaOH) and 5% calcium hypochlorite [Ca(ClO) 2 ] (both as% weight of water) for durations of 2, 24, and 72 h, respectively. The effect of these treatments on the compressive strength, splitting tensile strength, water permeability, thermal conductivity and diffusivity of concrete was investigated. Results show that Ca(ClO)2 has a more positive effect on the strength and permeability compared to NaOH solution and water. Experimental results were statistically analyzed using ANOVA and Post Hoc tests. The analyses showed that the improvement of concrete strength is only significant when the treatment with NaOH and Ca(ClO) 2 is prolonged to 72 h. Furthermore, the microstructural analysis of concrete showed that the improvement in the strength is due to the improved bonding between cement paste and rubber aggregates as a result of surface treatment. This microstructural improvement also resulted in lower water permeability of concrete. However, the thermal conductivity and diffusivity increased when the surface treatment duration increases as there are less air voids in the samples. This study shows that, with appropriate pretreatment, a certain percentage of natural aggregates can be safely replaced with waste tire rubber aggregates while maintaining sufficient quality of the resulting concrete.

Enhancement of Mechanical Properties and Porosity of Concrete Using Steel Slag Coarse Aggregate

“…Though crushed stone aggregates are used in the concrete industry due to rapid urbanization, they are mostly imported from abroad, thereby, increasing the cost of concrete production. Due to the aforementioned issues, indeed, it is necessary to find possible alternative construction raw materials that can be used as coarse and fine aggregates in concrete construction works [4][5][6].…”

Uso Del Caucho De Neumáticos Triturados Y Aplicados Al Concreto: Una Revisión Literaria

“…Los resultados reflejan que la cohesión de la mezcla aumentó y el ángulo de fricción interna disminuyó con respecto al suelo natural, resultando en la suma de un aumento de la resistencia al corte. (Khern et al, 2020), en su estudio demostraron que, con la incorporación de caucho proveniente de neumáticos, reduce la resistencia, aumenta la permeabilidad y disminuye la conductividad térmica del concreto. Sin embargo, solo unos pocos estudios han investigado el efecto de los agregados de caucho de superficie modificada sobre las propiedades del concreto.…”

Silane Coupling Agent Modification Treatment to Improve the Properties of Rubber–Cement Composites

“…14,15 Rubber, which is an organic polymer material, has poor affinity to the cement matrix, 16 and the interfacial layer between them forms a weak zone of the composite. 2,17,18 This cement− rubber interfacial transition zone can adversely affect the mechanical properties and durability of the composite, which has gained considerable attention. 19,20 Solving the compatibility of waste rubber and cement-based materials is an important prerequisite for the effective utilization of this composite material.…”

“…The non-degradability of waste rubber constitutes a huge environmental burden. , Despite the variety of current recycling methods available, some disposal methods still cause environmental and health-related problems, − and the output of waste rubber is on the increase. − The recycling of waste rubber as an aggregate in cement-based materials has become one of the alternatives to maintain the ecological balance with economically meaningful added value. − Experimental results have shown that rubber in cementitious materials can trigger serious strength landslide problems. , Rubber, which is an organic polymer material, has poor affinity to the cement matrix, and the interfacial layer between them forms a weak zone of the composite. ,, This cement–rubber interfacial transition zone can adversely affect the mechanical properties and durability of the composite, which has gained considerable attention. , Solving the compatibility of waste rubber and cement-based materials is an important prerequisite for the effective utilization of this composite material.…”