How to Cure Concrete in Cold Weather? Curing concrete becomes a more challenging job in colder days. Heavy snowfall and excessive humidity in the air are a few typical sights of the winter season which prevent concrete slabs from hardening properly in time. When temperature goes below 0 degree Celsius or minus 7 degree Celsius, … Read more
No Fines Concrete No fines concrete is one type of light weight concrete. As the name indicates, this a concrete mix without fine aggregate or sand. This type of concrete consists of only water, cement and coarse aggregate. Important Notes on No fines Concrete Normally coarse aggregates passing 20 mm sieve and retained on 10 … Read more
Special Materials in Concrete Industry 1. Ferrocement Ferrocement is a type of reinforced concrete composed of concrete with small aggregate (or coarse cement mortar), 12 to 30 mm thick, reinforced with a minimum of two layers of small diameter, orthogonally woven wire mesh separated by 3 to 6 mm diameter galvanized spacer wires or weld … Read more
Corrosion of Concrete Reinforcement Corrosion is a chemical process of destruction of material because of its reaction with the environmental conditions. The most predominant among various factors of corrosion is the atmospheric corrosion which causes the rusting of steel. Appreciable corrosion only starts when the relative humidity of the air exceeds around 65%. In dry, … Read more
Recommended Procedures for Concrete Inspection The following procedures have been found worthwhile, to enhance the probability of carrying out the intent of the designs and specifications on a large variety of projects. This results in a completed facility that will properly ensure the purpose for which it is intended, at minimum maintenance cost. The purpose … Read more
Laboratory Rules of Safety and Procedures The following safety regulations apply to all individuals engaged in testing as well as to those who even casually enter the concrete laboratory area: Rule-1 SMOKING— Strictly forbidden within any of the laboratory areas. Rule-2 CLOTHING—Everyone should provide themselves with suitable work clothes, of substantial quality, in good repair, … Read more
Different Test Methods for Workability Measurement Depending upon the water cement ratio in the concrete mix, the workability may be determined by the following three methods. Slump Test Compaction Factor Test Vee-bee Consistometer Test 1. Slump Test Suitability This method is suitable only for the concrete of high workability. This test is carried out with … Read more
Sand Equivalent Value Test Purpose To determine the percent of undesirable particles in the fine aggregate fraction used in the design of Portland cement concrete mixtures. The method is also applicable for determining the relative proportions of detrimental fine dust or claylike material in soils. Equipment and Materials The Sand Equivalent test kit consists of … Read more
Tensile Strength Test of Hydraulic Cement Mortars Purpose Determination of the tensile strength of hydraulic cement mortars using briquet specimens. Equipment and Materials 2 kg scale accurate to 0.1 gram Briquet molds Small steel trowels Clips for holding the test specimens Testing machine capable of applying the load at a rate of 2.67 ± 11 … Read more
Test for Density of Hydraulic Cement Purpose Determination of the density of hydraulic cement in connection with the design of Portland cement concrete mixtures Equipment and Materials Standard Le-Chatelier Flask as shown below Heavy rubber pad about 12 in. × 12 in. square Lead ring weight to fit around stem of the flask Funnel Thermometer … Read more