Title: Role of Superplasticizers in Gypsumless Portland Cements

Author(s): J. Hrazdira

Publication: Symposium Paper

Volume: 148

Issue:

Appears on pages(s): 407-414

Keywords: clinker; compressive strength; consistency tests; pastes; portland cements; setting (hardening); sodium carbonate; superplasticizers; Materials Research

DOI: 10.14359/4114

Date: 9/1/1994

Abstract:
Gypsumless portland cements (GPC) are inorganic binders that may be described as systems of ground portland clinker with a specific surface of 400 to 500 kg/m 2 (Blaine), a superplasticizer with hydroxyl groups, and a hydrolyzable alkali metal salt. The major feature of GPC is the use of a low water-cement ratio (under 0.30), based on the strong liquefying action of the superplasticizer and alkali salt in suspension of ground clinker in the absence of gypsum. The effect of the dosage of sodium lignosulfonate in combination with sodium carbonate on compressive strength, setting time, and consistency of cement paste was studied. It was found that paste properties strongly depend on dosage and mutual ratio of the admixtures. The optimum composition of the setting and liquefying regulator causes high compressive strengths 3 to 7 hr after mixing of binders (15 to 45 MPa).