The mechanical properties and heat development behavior of high strength concrete containing high fineness coal bottom ash as a pozzolanic binder

There have been few studies reported on the influence of the use of coal bottom ash as a partial substitute for cement on the properties of high strength concrete. The work aims to assess the effect of the use of ground coal bottom ash (GBA) as a pozzolan substitute for ordinary Portland cement (OPC) on the properties of high strength concrete. The partial substitution of OPC with GBA at 15-45 wt% of binder was attempted to produce high strength concrete. The properties of concrete in terms of the slump loss, heat development, compressive strength, and modulus of elasticity (E-c) were evaluated. The results showed that the grinding of coal bottom ash improved its quality by achieving high fineness, and it could be used to produce high strength. Furthermore, such treatment also reduces the slump loss of fresh concrete containing the GBA. All concrete containing GBA exhibited compressive strengths of more than 55 MPa, except for the concrete with 45% of GBA at 7 days. The E(c )values of GBA concrete increased along with the compressive strength and were similar in terms of magnitude to those of conventional concrete. Moreover, the use of GBA as a pozzolan could reduce the heat development. The heat development rate of GBA concrete was approximately 2 times lower than that of the conventional concrete made by using only OPC as a binder when using the GBA as a substitute for OPC when a rate of 45 wt% of binder was introduced into the concrete mixture. GBA can be used as a substitute material for cement to control the temperature of high strength concrete while maintaining a favorable mechanical strength. Such use also provides an avenue for the high value reuse of the waste mate- rial as a useful construction material. (C) 2020 Elsevier Ltd. All rights reserved.