Highway Research Record

II. PAVEMENT ENGINEERING AND PAVING MATERIALS
3. RIGID PAVEMENT
ON GOING PROJECTS
Strength and Durability Studies of Plain and Reinforced Concrete using Blended Cements

Duration: December 2002
Central Road Research Institute, New Delhi (R)

Present Status and Progress
In continuation of the work reported earlier, long term (one year) compressive and flexural strengths of M-40 grade concrete made with blended cements (replacing 15, 25 & 35 percent flyash and 35, 50 and 65 percent ground granulated blast furnace slag) were determined. Corrosion behaviour of rebar embedded concrete cube specimens prepared by using OPC, PPC and blended cements with 45 mm and 70 mm cover thicknesses was studied upto the age of 9 months by (i) determination of Open Circuit Potential of specimens after exposure to wetting and drying cycles in 3 percent sodium chloride solution and (ii) carbonation method. No sign of corrosion was observed. In M-40 grade concrete, direct replacement of OPC with 15 percent good quality flyash, gives compressive and flexural strengths, both, at par with OPC concrete upto the age of 28 days (except early strength i.e. at 3 days due to slow reaction). However, at higher ages i.e. 90, 180, & 365 days there is appreciable increase in strengths. By replacement of higher percentages of OPC with flyash i.e. 25 & 35 percent , longer age strengths are improved.

Reports/Publications

“Flyash Based Portland Pozzolana Cement in Concrete Pavement Construction – Technical and Economic Aspects” published in Proceedings of National Seminar on “Building Materials and Technology for Sustainable Development”, organised by CEPT, 21-22nd Jan. 2005 at Ahmedabad.