The system ground clinker-polyphenol sulphonate-alkali metal salts (the Gypsum-Free portland cement)
✍ Scribed by František Škvára; Mirka Rybinová
- Publisher
- Elsevier Science
- Year
- 1985
- Tongue
- English
- Weight
- 839 KB
- Volume
- 15
- Category
- Article
- ISSN
- 0008-8846
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✦ Synopsis
The sulphonated product of condensation of phenols with formaldehyde (polyphenol sulphonate) reacts synergistically with the alkali metal carbonate (bicarbonate, silicate) as a strong liquefying system in suspension of ground clinker of Portland cement.
The liquefying effect of the polyphenol sulphonate-carbonate system enables the preparation of suspensions that possess practically Newtonian behavior without yield value under low water-to-cement ratio (as high as 0.20). The synergistic influence of the polyphenol sulphonate-carbonate (bicarbonate) system substitutes for the regulation reaction of gypsum in pastes or concretes.
The ground clinker (without gypsum) with a specific surface of 250-700 m2/kg--polyphenol sulphonate--alkali metal carbonate (bicarbonate) represents a new type of binding agent that differs from the conventional Portland cement by good rheological qualities of pastes under low water-cement ratios, by short and long term strength (compressive strength 20-40 MPa after 4-5 hours, 60-100 MPa at 24 hours), by the ability of setting and hardening under low and below zero temperatures, by a quick strength rise at short time with elevated external temperature (steam curing), and high resistance to aggressive media and high temperatures.
The microstructure of hardened pastes made of gypsum-free Portland cements differs from the classic Portland cements by a high compactness and by the absence of characteristic portlandite crystals.