2019 CSCE Annual Conference - Laval (Greater Montreal)

2019 CSCE Annual Conference - Laval (Greater Montreal) Conference

Development of Bendable Concrete And Rigid Pavement Overlay Application

Mr. Omar Ragab, The American University in Cairo
Dr. Safwan Khedr, The American University in Cairo
Mr. Mohamed Abdel Mooty
Dr. Maram Saudy, The American University in Cairo
Mr. Khaled Hashim
Mr. Ali Ahmed, American University in Cairo
Mr. Omar El Sherbini
Mr. Omar El-Kadi, The American University in Cairo
Mr. Omar El Shazly, The American University in Cairo
Mr. Ahmed Hassabelnabi, The American University in Cairo (Presenter)

Concrete is one of the most ubiquitous materials around the world, especially in the construction industry. However, its single downfall is its brittle nature, but this paper aims at making concrete bendable.

Engineered Cementitious Composite or ECC is a ductile fiber reinforced mortar that exhibits higher flexural capacity, higher deformation capability before failure, and significantly reduced crack width, opposed to conventional concrete.

The main factor contributing to these enhancements is the polyvinyl alcohol (PVA) fibers that have a high tensile strength and modulus of elasticity, which decrease the brittleness of conventional concrete. Other factors include the absence of coarse aggregates to ensure the homogeneity of the mix and the proper dispersion of the PVA fibers.

The mix design of the ECC proposed in previous work consists of Cement, Fly Ash, very fine sand, PVA fibers, water, and superplasticizer. However, to make it relevant to Egypt, this paper aims to replace the Fly Ash with much cheaper locally produced Silica Fume and hence, changing the mix design of the bendable concrete.

In this paper, the experimental program is to include tests to measure the flexure strength of prisms, obtain stress strain curves of cylinders, obtain tensile stress strain curves of dog bone shaped mold, and measure the performance through dynamic loading. This experimental program is to be conducted on various mixes, with the concrete mortar being the control mix that will be compared to that of ECC with Fly Ash, and ECC with silica fume at different Silica Fume percentages.

The expected outcome of these tests would show enhanced ductile and flexural properties of the ECC mixes containing Silica Fume and Fly Ash as compared to that of conventional concrete. Additionally, it is expected that the Silica Fume mixes will have similar characteristics in regard to tensile strength and flexural capability to that of Fly Ash; therefore, the locally produced Silica Fume is expected to be a more feasible and practicable ECC mix in Egypt.

 ECC shows great promise to be applied in many aspects in the construction industry due to its ductile nature and energy dissipating properties; therefore, this paper plans to study the effect of using the ECC as a pavement overlay to extend the road service life. This is to be studied practically through an experimental model and finite element analysis of that model.