مختصر البحثIn this study, reduced scale wall models were used in this research (which are believed to resemble as much as possible field conditions) to study the shrinkage behavior of reactive powder concrete (RPC) base restrained walls. Six base restrained RPC walls were casted in different length/height ratios for two ratio of steel fiber by volume in Summer. These walls were base restrained by reinforced concrete bases to provide the continuous base restraint to the walls. The mechanical properties of reactive powder concrete investigated were; compressive strength between (75.3 – 140.1) MPa, splitting tensile strength between (5.7 – 13.9) MPa, flexural tensile strength (7.7 – 24.5) MPa, static modulus of elasticity (32.7 – 47.1) GPa. Based on the observations of this work, it was found that the cracks did not develop in the reduced scale for reactive powder concrete (RPC) walls restrained from movement at their bases for different L/H ratios (2, 5, and 10) and for two ratio of steel fiber (1% & 2%) during 90 days period of drying conditions. Also, the shrinkage values increase toward the edges. Based on the results of this work, the increasing in maximum shrinkage values for walls with 1% steel fiber were (29%, 28%, 28%) of the maximum shrinkage values for walls with 2% steel fiber for length/height ratios (2, 5, and 10) respectively. The experimental observation in beam specimens showed that the free shrinkage (at date of cracking) of beams with 1% steel fiber was higher than the free shrinkage of beams with 2% steel fiber about (24%), the tensile strain capacity (at date of cracking) of beams with 1% steel fiber was higher than the tensile strain capacity of beams with 2% steel fiber about (45%). The elastic tensile strain capacity (at date of cracking) of beams with 1% steel fiber was higher than the elastic tensile strain capacity of beams with 2% steel fiber about (42%).
