In:
Canadian Journal of Civil Engineering, Canadian Science Publishing, Vol. 35, No. 12 ( 2008-12), p. 1435-1445
Abstract:
Two Pakistani volcanic ashes, VA1 (as is and calcined) and VA2 (as is), were incorporated into mortar cubes, concrete cylinders, and concrete beams as a partial substitute for ordinary Portland cement (OPC), and were studied in detail. The X-ray diffraction patterns showed that both ashes possessed crystalline as well as amorphous phases. The pozzolanic activity index (PAI) of VA1 at 7 d was below 75%, whereas it was 80% at 28 d. The pozzolonic activity indices in OPC mortars containing VA2 were much higher than those for VA1, both at 7 and 28 d. In mortar cubes and concrete cylinders, approximately the same compressive strengths were observed in samples containing 100% cement as in those incorporating a 10% replacement of cement by either VA1 or VA2. Mortar cubes soaked in 5% sodium sulphate solution demonstrated consistently improved resistances to sulphate attack as ash content increased in the mortar. Similar results were also observed in water absorption tests. Modulus of rupture of all concrete beams decreased as the levels of VA1 and VA2 increased from 10% of OPC content to 40%. Rupture moduli were higher for VA1 than for VA2 at all cement replacement levels.
Type of Medium:
Online Resource
ISSN:
0315-1468
,
1208-6029
Language:
English
Publisher:
Canadian Science Publishing
Publication Date:
2008
detail.hit.zdb_id:
1490923-6
