Use of ASTM D8058 Flexural Strength Test Method to assess overall GCCM performance

Abstract

ASTM D8058, a flexural strength test, is currently used as the main index test for Geosynthetic Cementitious Composite Mats (GCCMs) within Factory Production Control and is also used to assess comparative performance of GCCMs for durability and chemical resistance testing. This paper provides an overview of the suitability of ASTM D8058, three-point flexural strength test as an indicative method for assessing overall GCCM performance. Specifically, this paper will look at the relationship between GCCM Initial Flexural Strength (IFS) values obtained using ASTM D8058 and characteristics associated with the cementitious fill material. It also recommends further research to assess the relationship between Final Flexural Strength (FFS) values and characteristics associated with the geosynthetic components of the GCCM. IFS is obtained at the end of the first stage of a three-point bending test in the form of the first peak that is observed when the cementitious material first cracks in the tested specimen. The value of that first peak is mainly governed by the strength of the cementitious component of the GCCM. The relationship between IFS and the following GCCM properties is examined: Dry (uncured) mix density, Hardened (cured) density, Comressive strength development, Resistance to abrasion, Freeze and thaw durability and Resistance to chemicals.