Shock wave propagation in micro-mechanics based Representative Volume Element of cement paste

Abstract

Shock wave propagation in a synthetic representative volume element (RVE) of Type-I Portland cement paste has been analyzed. The existence of unhydrated water, nano/micro pores, and other hydrated and unhydrated products such as calcium silicate hydrate (C-S-H) and four main clinkers (tricalcium silicate, dicalcium silicate, tricalcium aluminate and tetracalcium aluminoferrite) create a complex microstructure in cementitious materials. The objective is to analyze the heterogeneity induced shock wave decay phenomenon under compression caused by the plate impact of a copper flyer. The shock wave response of cement paste as a heterogeneous material is highly influenced by these constituents and their relative amount. The effective material properties of the RVE have been obtained by imposing appropriate boundary conditions. The stress wave propagation of both heterogeneous RVE and homogeneous media are presented and compared when the effective material properties are considered for all phases in homogenous RVE. The results clearly show the effect of heterogeneity on the stress wave propagation as well as attenuation and shock wave decay phenomena. Lastly, the effects of spatial distribution, material properties and volume fraction of particles on velocity profiles at the rear surface of an RVE are investigated and results show that how they affect the heterogeneity that lead to attenuation.