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.

This paper reports on the characteristics of drying shrinkage and creep of steel chip reinforced cementitious composite (SCRCC). In this study, first, four restrained wall specimens made of normal mortar and SCRCC with various numbers of steel reinforcing bars (4 or 10) were prepared to compare drying shrinkage characteristics. The specimens were restrained on the rigid laboratory floor so that shrinkage cracks were induced. The drying shrinkage strains were measured by the contact gauge method and compared with unrestrained small specimens. The number of cracks was simultaneously observed. Second, bond tests were prepared to evaluate the bond characteristics between the SCRCC and the steel bar. Third, creep tests were performed to improve the accuracy of the analysis of the drying shrinkage behavior. Twelve block specimens were made and a constant flexural load was applied for 7, 14, and 28 days. The observed shrinkage strains and creep strains of SCRCC were modeled according to CEB-FIP Model Code 1990. These models were incorporated with bond computation between the SCRCC and the steel bar to predict the number of drying shrinkage cracks. The computed equivalent number of cracks based on the shrinkage strain model, the creep model, and the bond model derived from a pull-out test generally agreed with the test results.

Nitrite-type hydrocalumite (calumite) is a material that can adsorb the chloride ions (Cl -)that cause the corrosion of reinforcing bars and liberate the nitrite ions (NO2 -) that inhibit corrosion in reinforced concrete, and can provide a self-corrosion inhibition function to the reinforced concrete. In this study, VA/E/MMA-modified mortars with calumite were prepared with various calumite contents and polymer binder-ratios, and tested for corrosion inhibition, chloride ion penetration, carbonation and drying shrinkage. As a result, regardless of polymer-binder ratio, the replacement of ordinary Portland cement with hydrocalumite has a marked effect on the corrosion inhibiting property of the polymer-modified mortars. However, chloride ion penetration and carbonation depths are somewhat increased with higher calumite content, but can be remarkably decreased depending on the polymer-binder ratios. The 28-d drying shrinkage shows a tendency to increase with the polymer-binder ratio and calumite content. VA/E/MMA-Modified mortars with 10 % calumite did not satisfy KS requirements. Accordingly, a calumite content of 5 % is recommended for the VA/E/MMA-modified mortars with calumite.

This study investigates characteristics of drying shrinkage and creep of "Steel Chip Reinforced Cementitious Composite (SCRCC)". Firstly, four restrained wall specimens made of normal mortar and the SCRCC with varied amount of steel reinforcing bars (4 or 10) are prepared to compare the drying shrinkage characteristics. The specimens are restrained on rigid laboratory floor so that shrinkage cracks are induced. The drying shrinkage strains are measured by contact gauge method and compared with unrestrained small specimens. Number of cracks are simultaneously observed. Secondly, creep test is carried out to improve accuracy of analysis of the drying shrinkage behaviors. Twelve block specimens are made and constant flexural load is applied for 7, 14, and 28 days. The shrinkage strains and creep strains of SCRCC are modeled by modifying CEB-FIP Model Code 1990. These models are incorporated with bond computation between SCRCC and steel bar to predict the number of drying shrinkage cracks.