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
Test for Clay Lumps and Friable Particles Purpose Clay and friable particles may be present in the form of lumps in natural aggregates. If they are near the surface, these lumps can cause pitting under the influence of traffic. Specifications frequently limit these particles to a maximum of 1%. Equipment and Materials Weighing device accurate … Read more
Compressive Strength Test of Hydraulic Cement Mortar Purpose The following covers only that portion of ASTM Designation: C 109 that is required to determine the compressive strength of 50 mm (2 inches) of Portland cement mortar cubes. Equipment and Materials A 2kg scale accurate to 0.1 gram Six 50 mm (2 inch) cube molds Hard … Read more
Advantages of Prestressed Concrete Most of the prestressed members are precast and therefore all the advantages or precast concrete hold true for prestressed concrete also. To know the advantages of precast concrete click here. In addition, there are advantages to be gained by prestressing when conditions are favorable to its use. Following additional advantages due … Read more
Placing of Concrete in Hot Weather For normal concreting operations the temperature of concrete should vary between 150C to 250C to enable it to attain its full ultimate strength within 28 days. In case concreting is carried out in extreme hot weather conditions, the rate of hydration of cement gets accelerated and the water in … Read more