This study was performed to resolve the problem of cracks caused by the rapid hydration heat produced during the early setting stages of rapid-hardening cement. To address the hydration heat of rapid-hardening cement, we prepared a modified rapid-hardening cement using calcium sulfoaluminate clinker combined with a styrene butadiene (SB) polymer. The performance of SB polymeric emulsion-modified concrete made from modified rapid-hardening cement was assessed by determining shrinkage (change in length, and plastic and autogenous shrinkage). The modified rapid-hardening cement in combination with SB polymeric emulsion effectively reduced cracking. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 112: 2229-2234, 2009