Abstract
This study is to investigate the influence of the over-added chemical agents, such as water reducing agent(WRA) and AE water reducing agent(AEWRA), on the physical properties of concrete to estimate the degree of damage due to over-added chemical agents. For the fresh concrete, slump and slump flow increased with the increase of WRA and AEWRA as expected. Material segregation phenomenon was observed with the over dosage of lignin based AEWRA about 4 times larger than recommended dosage. The over dosage of AE water reducing agent about 4 times larger than recommended dosage resulted in an increase of air contents remarkably. The set retardation occurred greatly with the increase of AEWRA and WRA. For the properties of the hardened concrete corresponding to the over dosage of AEWRA, it is found that compressive strength of over added AEWRA and WRA concrete are much smaller than those of base and recommended dosage concrete proportionally due to associated increasing air content.
