Cooperative stabilization of calcium carbonate powder, blast furnace slag, and white cement in composite concrete: Volume variation and hydration behavior

Volume stability was an important property of white concrete in long-term service. The purpose of this research is that volume stability of composite concrete was advanced by synergy of calcium carbonate powder and blast furnace slag , and its related hydration behavior was revealed. The results manifested that the early shrinkage, dry shrinkage, and creep of calcium carbonate powder-blast furnace slag-based white concrete (C20) were the lowest as content of calcium carbonate powder and blast furnace slag were 20 % and 10 %. Furthermore, early shrinkage, dry shrinkage, creep, and 120-days compressive strength of C20 were 52.49 %, 24.83 %, 22.47 %, and 82 MPa respectively, which superior to those of others white concrete. These results indicated that the long-term volume stability and strength of C20 was optimal. Information of hydration heat showed that accumulate hydration heat about C20 was minimum (226.91 J/g). This find proved that the effects of thermal expansion and cooling shrinkage on the volume of C20 were ameliorated efficiently. The results of microstructure, mineral phase, and pore structure demonstrated that dense degree of white concrete was boosted by flocculation gel product and rod ettringite . Therefore, the volume stability of white composite concrete could be enhanced by synergy of calcium carbonate powder, blast furnace slag, and white cement. • 1 Novel composite white concrete is created by CaCO 3 powder and blast furnace slag. • 2 Properties of white concrete is enhanced by CaCO 3 powder and blast furnace slag. • 3 Synergy of 20 % CaCO 3 , 10 % furnace slag, and 70 % white cement (C20) is optimal. • 4 Volume stability of C20 is ameliorated by low hydration heat and hydration products. • 5 Micromorphology density of C20 is improved from flocculent gel and rod-like ettringite.