Research Articles | Challenge Journal of Concrete Research Letters

Degree of hydration of OPC and OPC/FA pastes dried in different relative humidity

Nasir Shafiq, Muhd Fadhil Nuruddin


In this research; the degree of hydration of the pastes and the compressive strength of the 50 mm cubes prepared with the 100% cement and fly ash blended cement was determined. 24 hours after casting mortar cubes and the paste samples were cured for 28 days in the fog room. After 28 days curing; a set of 3 cubes and a paste sample was dried in the 100%, 75%, 65%, 40% and 12% ambient relative humidity at the constant temperature of 27oC. Drying conditions showed significant effects on the compressive strength and the degree of hydration. Highest compressive strength of 70 MPa was measured for mortar cubes dried in 100% RH; similarly 97% degree of hydration was determined for 100% cement samples dried in the 100% RH. For mortar cubes dried in 12% RH, the compressive strength was measured between 47 and 53 MPa. The similar paste samples showed the maximum degree of hydration as 81%.


cement hydration; calcium hydroxide; fly ash; drying conditions

Full Text:



Powers, T C, and Brownyard, T L, (1948) Studies of the physical properties of hardened Portland cement paste, Portland Cement Association, research bulletin, No. 22.

Nilsson, L O, (1980) Hygroscopic moisture in concrete – drying, measurement and related material properties, Lund Institute of Technology, Report, TVBM 1003, Lund.

Nasir Shafiq, (1999) Transport characteristics of fluid and ions in concrete: A criteria for concrete durability, PhD Thesis, University of Leeds, UK.

Midgley, H G; (1979) The determination of calcium hydroxide in set Portland cement”, Cement and Concrete Research, Vol. 9, pp. 77-82.

Cabrera, J G, and Hassan K E-G, (1994) Assessment of the effectiveness of surface treatments against the ingress of chlorides into mortar and concretes, Corrosion and Protection of Steel in Concrete, International Conference, Sheffield (UK), Swamy, R N (Ed.), pp. 1028-1043.

Keattch, C J, and Dollimore, (1975) D, Introduction to Thermogravimetry, , Heydon 45.

Cabrera, J G, and Lynsdale, C J, The effect of superplasticisers on the hydration of normal Portland cement, (1996), Cemento, pp. 532-541.

Dweck J, Buchler P M, Coelho ACV and Cartledge F K, (2000) Hydration of Portland cement blended with calcium carbonate, Thermochemica Acta, , 346, pp: 105-113.

Alarcan-Ruiz L, Platret G, Massieu E and Ehrlacher A, (2005) The use of thermal analysis in assessing the effect of temperature on a cement paste, Cement and Concrete Research, , 35, pp: 609-613.

Jawed, I, Skalny, J, Bach, T, Schubert, P, Bijen, J, Grube, H, Nagataki, S, Ohga, H, and Ward, M A, (1991) Hardened mortar and concrete with fly ash, RILEM Report, Fly Ash in Concrete: Properties and Performance, , Wesche, K (Ed.).

Cabrera, J G, and Lynsdale, C J, (1995) The effect of superplasticisers on the hydration of normal Portland cement, Proceedings of the international conference on Advances in Concrete Technology, Las Vegas (USA), pp. 741-751


  • There are currently no refbacks.