Prediction of Drying Shrinkage Cracks of Steel Chip Reinforced Polymer Cement Mortar

Abstract

This paper describes experimental and analytical study of drying shrinkage crack behavior of steel chip reinforced polymer cement mortar (SCRPCM) and polymer cement mortar (PCM). (1) Drying shrinkage test is conducted with four restrained wall specimens of 2500 mm length and 150×300 mm cross section. The drying shrinkage strains, the number of cracks and the crack patterns of the specimens are observed. (2) (a) flexural creep test, (b) pull-out bond test and (c) bond creep test are carried out to evaluate the bond between the SCRPCM/PCM and the steel bar as well as creep characteristics. The shrinkage strains and creep strains of SCRPCM/PCM, and the bond stress-slip curve and bond creep of steel bars are modelled partially according to CEB-FIP Model Code. These models are incorporated with bond computation between the SCRPCM and the steel bar to predict effective strain. The bond stress distribution is computed using analytical solutions of the differential equation of the bond problem, and crack numbers are predicted. (3) 2D finite element analyses are conducted for the four restrained wall specimens of SCRPCM/PCM subjected to drying shrinkage to practically simulate the crack behaviors. The analyzed crack patterns, number of cracks and crack widths are compared with the result of drying shrinkage test.