Performance Test and Microstructure of Modified PVC Aggregate-Hybrid Fiber Reinforced Engineering Cementitious Composite (ECC)

Abstract

This study aims to solve the problems of the high cost, heavy pollution and poor performance of traditional engineered cementitious composites (ECC) by adding modified Polyvinyl chloride (PVC) aggregate, Polypropylene (PP)–Polyvinyl alcohol (PVA) hybrid fiber and large amount of fly ash. The PVC aggregate is modified by pre-coating silica fume with a PP fiber volume content of 0.5%, PVA fiber volume contents of 1%, 1.5%, and 2%, PVC aggregate contents of 10%, 20%, and 30%, and fly ash volume content of 69%. Different properties and microstructures were studied by carrying out cube compression tests, splitting tensile tests, water absorption tests, drop hammer impact tests, scanning electron microscopy and nuclear magnetic resonance tests. According to the test results, under the same content of PVC aggregate, the use of modified PVC aggregate can, not only effectively avoid the decrease in strength and increase of water absorption, but also improve brittleness and impact failure energy. Regardless of the kind and content of fiber, the compressive strength and brittleness will decrease, while the splitting tensile strength, water absorption, and impact failure energy will increase. After adding 0.5% PP and 1.5% PVA fiber, the performance is ordinary and a negative mixing effect occurs. As more modified PVC aggregate is added, the strength of the ECC concrete with PP–PVA hybrid fiber and modified PVC aggregate added slowly decrease, while the water absorption and impact failure energy increase. Based on a comprehensive analysis of the test data, the reinforcement method of adding 1.5% PVA-0.5% PP hybrid fiber-30% modified PVC aggregate is superior to adding 1.5% PVA fiber, but slightly inferior to adding 2% PVA fiber. This study argues that the reinforcement method is of great significance for the promotion and application of ECC.

Experimental Investigation on the Effect Polypropylene Fibre and E-Waste Fibre Embedded in Concrete

“…Different types of fibre are used in concrete like steel fibres [4], glass [5], fibres of natural origin [6], carbon fibres [16]; Hybrid fibres [3,12]; as well as polymer fibres, i.e., polypropylene fibres [2,17] made of poly alcohol vinyl [7]. Fibre-reinforced concretes (FRC) increase various properties of concrete, including: compressive strength more than ordinary concrete [5,3,7]; greater tensile strength [6,7,8] higher bending and splitting tensile strength and ductility [12]; greater flexural strength [5]; high impact loading resistance [9]; high dynamic resistance [17], improve unity of structure [11]; crack formation is delayed even after fresh state (post-cracking of concrete) [6,11]; elastic modulus, shrinkage control. The ability of fibre is to reduce cracks at maximum strain and increases its ductility also durability which reduces transport of corrosive material into concrete [2,10].…”