Adhesion of Fiber-Reinforced Concrete on Hardened Surfaces of High Strength Ductile Cementitious Composites

Makoto Kawakami 2Ammar Hassan 2Satoru Matsuoka 1

1. Landes Co. Ltd., Project Development Department (Landes Co.), 630-1Otchiai Maniwa, Okayama 719-3192, Japan
2. Akita University, Faculty of Engineering and Resource Science, Dept. of Civil and Environmental Engineering (Akita Uni.), 1-1 Tegata Gakuen-cho, Akita 010-8502, Japan

Abstract

High strength ductile cementitious composite materials are gradually establishing a foothold in the application-field of construction engineering. Although these materials have improved properties, their cost is still comparatively high and they usually necessitate special manufacturing and curing procedures, which limits their use to precast elements. Consequently, one of the more economically feasible applications of these materials is using them in conjunction with ordinary concrete.

The application of the ductile cementitious composites together with ordinary concrete requires studying the bond characteristics between those two different materials. This paper reports the results of a research program of slant shear tests on cylinders made of the two materials.

The study focused on the adhesion of fresh concrete on hardened surfaces of high strength ductile cementitious composites. Slant shear tests were carried out on composite cylinders with a substrate of fiber-added ductile cementitious composites and an overlay of ordinary concretes with different fiber contents. The studied parameters of the tests were mainly the fiber content of the overlay concrete, the surface treatment and roughness of the cementitious material substrate, and the type of the cementitious material substrate.

The paper describes the tests and details the results. Failure stresses, bond strengths, and failure patterns were thoroughly discussed. The effects of each of the test parameters on the adhesion were also studied. A numerical analysis of the slant shear method was done and friction coefficients of the surfaces were calculated. The Mohr-Coulomb failure envelops under certain conditions were also presented and discussed. The paper outlines recommendations concerning surface treatment and the choice of materials for the different targeted applications.

 

Presentation: poster at E-MRS Fall Meeting 2005, Symposium G, by Makoto Kawakami
See On-line Journal of E-MRS Fall Meeting 2005

Submitted: 2005-05-30 11:38
Revised:   2009-06-07 00:44