CONCRETE

[:ru]Ван В.[:en]Wang W.[:] [:ru]доктор наук, инженер, менеджер отдела, Шанхайский инженерно-исследовательский центр строительных добавок, Шанхай, КНР[:en]Ph.D., Engineer, Department manager, Shanghai Sunrise Polymer Material Co., Ltd., Shanghai Engineering Research Center of Construction Admixtures (CAERC), Shanghai, P.R. China[:]

[:ru]Ден З.М.C.[:en]Deng Z.M.S.[:] [:ru]инженер, менеджер отдела, Шанхайский инженерно-исследовательский центр строительных добавок, Шанхай, КНР[:en]Engineer, Department manager, Shanghai Sunrise Polymer Material Co., Ltd., Shanghai Engineering Research Center of Construction Admixtures (CAERC), Shanghai, P.R. China[:]

[:ru]Фу Л.[:en]Fu L.[:] [:ru]доктор наук, старший инженер, управляющий директор, Шанхайский инженерно-исследовательский центр строительных добавок, Шанхай, КНР[:en]Ph.D., Senior engineer, Managing director, Shanghai Sunrise Polymer Material Co., Ltd., Shanghai Engineering Research Center of Construction Admixtures (CAERC), Shanghai, P.R. China[:]

Alitinform №4-5 (40) 2015 г. 76-85 p.

Abstract

The dosage efficiency of polycarboxylate-type superplasticizer (PCE) was severely diminished in presence of clay-bearing aggregates. Adsorption of PCE and PVA on bentonite were investigated with respect to tailoring molecular structure and competitive adsorption to find effective methods for weakening the sensitivity of PCE with clay-bearing aggregates. The results indicated that TPEG-based PCE (isopentenyl polyethylene glycol) has more excellent clay tolerance than MPEG-based PCE (methoxy polyethylene glycol). Increasing carboxyl density of main chain and side chain length of side chain of PCE molecule is favorable for weakening the sensitivity of PCE with clay-bearing aggregates. PVA can serve as sacrificial agent to weaken the PCE consumption caused by clay based on the severe competitive adsorption between PVA and PCE onto bentonite.

Key words:

polycarboxylate; superplasticizer; poly vinyl alcohol; bentonite; adsorption; concrete