Method of estimating the amount of fly ash in concrete

摘要

PROBLEM TO BE SOLVED: To measure the amount of fly ash in fresh concrete into which fly ash is incorporated easily and in a short time.;SOLUTION: Coarse aggregates collected to take out a sample are separated from fresh concrete into which fly ash is incorporated by wet screening (using a 0.5 mm sieve). Hydrochloric acid is added into a sample obtained by wet screening to dissolve cement and hydration products by a selective dissolution method, further followed by solid-liquid separation using centrifugal separation to separate cement and the hydration products. Fine aggregates having a low specific gravity are separated by heavy liquid separation using a sodium polytungstate solution (heavy liquid). The residual solid content is dried and weighed to estimate the fly ash amount (substitution rate) in the fresh concrete collected from the residual solid content.;COPYRIGHT: (C)2012,JPO&INPIT