IS Codes Used In Mix Proportioning IS 456 : 2000 Code of Practice for Plain & Reinforced Concrete Exposure Conditions Table 5 – Minimum Cement Content & Max. w/c ratio IS 10262: 2009 Mix Proportioning – Guidelines Table 1 – Standard Deviation Table 2 – Max. Water Content Table 3 – Vol. fraction of Coarse … Read more
Rehabilitation of RC, Steel and Pre-stressed Bridges Introduction Modern bridge infrastructure comprises of primarily concrete (reinforced or pre-stressed) and steel structures. Over the service life of a bridge, its constituent materials are continually subjected to fatigue and wear-tear due to dynamic vehicular loads. Overloading due to increase in wheel loads and regular exposure to aggressive external environment … Read more
Concrete Ingredients and Mixing of Concrete Definitions of Terms Associated with the Materials used in Concrete A.Portland Cement: a dry powder made by burning limestone and clay, and then grinding and mixing to an even consistency. B.Concrete: a mixture of stone aggregates, sand, portland cement, and water that hardens as it dries. C.Masonry: refers to … Read more
High Performance Concrete Concrete may be regarded as high performance for several different reasons: high strength, high workability high durability perhaps also improved visual appearance. High strength concrete (HSC) might be regarded as concrete with a strength in excess of 60MPa and such concrete can be produced as relatively normal concrete with a higher cement … Read more
Repair of Concrete Repair of Concrete Introduction This guide first discusses Reclamation’s methodology for concrete repair. It then addresses the more common causes of damage to Reclamation concrete, including suggestions of the types of repair methods and materials most likely to be successful in repair of concrete damage resulting from those causes. Finally, the guide … Read more
Fibre Reinforced Concrete Need? PCC has low tensile strength, limited ductility and little resistance to cracking. PCC develops micro-cracks, even before loading. Addition of small, closely spaced and uniformly distributed fibres act as crack arresters. Fibre Reinforced Concrete is a composite material consisting of mixtures of cement, mortar or concrete and discontinuous, discrete, uniformly dispersed suitable … Read more
What is Ferro cement? Definition “Ferro cement is a type of thin wall reinforced concrete, commonly constructed of hydraulic cement mortar, reinforced with closely spaced layers of continuous and relatively small size wire mesh. The mesh may be made of metallic or other suitable materials” -ACI Committee 549, 1980 Cement mortar is reinforced with layers … Read more
Fiber-Reinforced Concrete Historical Development Fibers have been used to reinforce brittle materials from time immemorial, dating back to the Egyptian and Babylonian eras, if not earlier. Straws were used to reinforce sun-baked bricks and mud-hut walls, horse hair was used to reinforce plaster, and asbestos fibers have been used to reinforce Portland cement mortars. Research … Read more
Concrete Mix Design Concrete is a construction material composed of : Cement (commonly Portland cement) as well as other cementitious materials such as fly ash and slag cement. Aggregate (generally a coarse aggregate such as gravel, limestone, or granite, plus a fine aggregate such as sand). Water and Chemical admixtures. The word concrete comes from … Read more