Compounds of Cement About 90-95% of a Portland cement is comprised of the four main cement minerals, which are C3S, C2S, C3A, and C4AF, with the remainder consisting of calcium sulphate, alkali sulphates, unreacted (free) CaO, MgO, and other minor constituents left over from the clinkering and grinding steps. The four cement minerals play very different … Read more
Portland Pozzolana Cement 1. Pozzolana Pozzolana is a volcanic powder found in Italy near Vesuvius A pozzolanic material is essentially a siliceous or aluminous material which possess no cementitious properties. But it has the property when it combined with lime to produce a stable pozzolana compound it has definite cementitious properties. In the presence of … Read more
Some Issues in the Usage of Fe- 500 or Higher Grade TMT Steel Bars in Residential Buildings Some contractors report a tendency among few design Engineers to specify Fe-500 or higher grade steel in residential buildings citing its high strength. Customers are advised that if they use Fe 500 or higher grade steel in building … Read more
Points to Consider Mixing of mineral admixtures with OPC at site should not normally be permitted. However for projects requiring use of blended cement from durability and strength considerations, which is not available from the cement manufacturer blending may be permitted through a specific facility created at site with complete automated process control to achieve … Read more
Reference IS: 650 – Standard sand for testing cement – specification Standard Sand Standard sand is used to assess the quality of cement, lime, pozzolana and other mineral admixture used in construction industry. Previously it was imported from U.K. Now it is available at Ennore, Madras. Characteristics Standard sand shall be of quartz material Colour … Read more
Types Of Cement and Respective Indian Standards SlNo Types Of Cement Reference Indian Standard 1 Ordinary Portland Cement 33 Grade IS:269 2 Ordinary Portland Cement 43 Grade IS:8112 3 Ordinary Portland Cement 53 Grade IS:12269 4 Rapid Hardening Cement IS:8041 5 Extra Rapid Hardening Cement — 6 Sulphate Resisting Cement IS:12330 7 Portland Slag Cement … Read more
What is Blended Cement Blended cement is obtained by mixing OPC with mineral admixtures or additives like fly ash, slag or silica fumes. Blended cements are now being considered superior as compared to conventional OPC category of cements. Advantages of Blended Cement The advantages of using blended cement can be broadly be divided in two … Read more
When a Portland Slag cement is tested for its physical requirements, then it must satisfy the following specifications given by IS 12269. The fineness value of PSC when tested by Blaine’s air permeability method shall not be less than 225 m2/kg. The expansion value (i.e. soundness) of unaerated cement when tested by Le-Chaelier method shall … Read more
When a calcined clay based Portland Pozzolana cement is tested for its physical requirements, then it must satisfy the following specifications given by IS 1489-Part 2. The fineness value of fly ash based PPC when tested by Blaine’s air permeability method shall not be less than 300 m2/kg. The expansion value (i.e. soundness) of unaerated … Read more
When a fly ash based Portland Pozzolana cement is tested for its physical requirements, then it must satisfy the following specifications given by IS 1489-Part 1. The fineness value of fly ash based PPC when tested by Blaine’s air permeability method shall not be less than 300 m2/kg. The expansion value (i.e. soundness) of unaerated … Read more