| Considerable progress has been made in the research and application of ultra-high performance over the last 20 years Concrete(UHPC),which displays exceptional mechanical properties and excellent durability.It has demonstrated huge potential Construction of next generation infrastructure from a sustainability perspective and Sludge powder(SP)is one of the supplementary cementing materials which contributes by hydraulic or pozzolanic action to the properties of hardened concrete.During the process of extracting tap water from the water works,the sludge is produced and is used to preserve the resource and environmental quality.This paper will give an overview on UHPC,with particular focus on the effect of modified sludge powder from water works on the properties of ultra-high performance of concrete.Supplementary cementitious materials for partial replacement of silica fume(SF)can be used to prepare ultra-high performance concrete(UHPC).The effect of SP to replace SF partially by weight used as a supplementary cementitious material(0%,15%,30%,45% and 60% of binder)on the compressive strengths,Flexural strengths and microstructure evolution of UHPC has experimentally been studied by multi-techniques including,scanning electron microscope and Nanoindentation technique.The results show that the use of SP degrades the microstructure of UHPC at early ages,and however,the use of SP with the appropriate content improves microstructure of UHPC at later ages.The hydration products of UHPC are mainly dominated by ultrahigh density calcium-silicate-hydrate(UHD C-S-H)and interfacial transition zone(ITZ)in UHPC has similar compact microstructure with the matrix.The use of SP improves the hydration degree of UHPC and increases the elastic modulus of ITZ in UHPC.SP is a good alternative to UHPC preparation for SF. |
