Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Development of High Strength Fly Ash/Portland Cement Concrete for Precast Industry
This paper reports results of an investigation performed to develop high-strength concrete incorporating increasing amounts of fly ash as an addition to high early strength, (type 30), Portland cement. Three water-to-cement ratios were used: 0.45, 0.40 and 0.35. The reference mixes had no fly ash while the fly ash/Portland cement concrete contained 20%, 30% and 40% of fly ash by weight of cement. The cement dosage was kept constant at 370 kg/m exp 3 . The fly ash was used as partial replacement of the fine aggregate. A superplasticizer was used to maintain the slump at 2-1/2 +- 1/2 inch while an air-entraining agent kept the air content within the desired level of 4.5 +- 1.0%. The results show that the incorporation of fly ash was not accompanied by a significant increase in the 1 day compressive strengths of the concrete when cured at room temperature (23 deg C +- 2 deg). At this temperature the fly ash reacts much too slowly and begins to improve the overall properties of concrete at the later age of 28 days. In order to accelerate the anticipated benefits of fly ash on the early strength of concrete, we would suggest to further this study to include heat curing of the concrete as is commonly practiced by the precast industry. 3 references, 3 figures, 11 tables. (ERA citation 10:022907)
Development of High Strength Fly Ash/Portland Cement Concrete for Precast Industry
This paper reports results of an investigation performed to develop high-strength concrete incorporating increasing amounts of fly ash as an addition to high early strength, (type 30), Portland cement. Three water-to-cement ratios were used: 0.45, 0.40 and 0.35. The reference mixes had no fly ash while the fly ash/Portland cement concrete contained 20%, 30% and 40% of fly ash by weight of cement. The cement dosage was kept constant at 370 kg/m exp 3 . The fly ash was used as partial replacement of the fine aggregate. A superplasticizer was used to maintain the slump at 2-1/2 +- 1/2 inch while an air-entraining agent kept the air content within the desired level of 4.5 +- 1.0%. The results show that the incorporation of fly ash was not accompanied by a significant increase in the 1 day compressive strengths of the concrete when cured at room temperature (23 deg C +- 2 deg). At this temperature the fly ash reacts much too slowly and begins to improve the overall properties of concrete at the later age of 28 days. In order to accelerate the anticipated benefits of fly ash on the early strength of concrete, we would suggest to further this study to include heat curing of the concrete as is commonly practiced by the precast industry. 3 references, 3 figures, 11 tables. (ERA citation 10:022907)
Development of High Strength Fly Ash/Portland Cement Concrete for Precast Industry
M. Plumat (Autor:in) / V. De Benedictis (Autor:in) / C. Bedard (Autor:in)
1982
27 pages
Report
Keine Angabe
Englisch
Solid Wastes Pollution & Control , Construction Equipment, Materials, & Supplies , Physical & Theoretical Chemistry , Fly Ash , Portland Cement , Additives , Compression Strength , Curing , Elasticity , Experimental Data , Flexural Strength , Heat Treatments , Tensile Properties , Waste Product Utilization , Foreign technology , ERDA/360603 , ERDA/010800 , ERDA/320305 , Solid wastes
Development of Heat-Curing Cycles for Portland Cement-Fly Ash Concrete for the Precast Industry
| British Library Conference Proceedings | 1987
Forged lift anchor for precast portland cement concrete shapes
| Europäisches Patentamt | 2017
High-early-strength concrete with Portland cement
| Engineering Index Backfile | 1936