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
Theory of Soil Compaction During compaction the reduction in volume is mainly due to expulsion of pore air and rearrangement of particles resulting in their closer packing. Compaction of a soil mass results in increase in dry density. The dry density attained depends on water content, amount and type of compaction. The amount and type … Read more
SOIL STRUCTURE / SOIL FABRIC The term soil structure in general, refers to the arrangement or state of aggregation of particles in a soil mass. But deeper understanding of soil structure demands consideration of mineralogical composition, shape and orientation of soil particles; the nature and properties of soil water, and the forces of interaction between … Read more
Types of Railway Yards The system of tracks laid usually on a fairly level ground for receiving, storing, sorting, making up trains and dispatch of vehicles, is known as railway yards. The railway yards are broadly classified as under Passenger yards Goods yards Marshalling yards Locomotive yards 1. Passenger Yards The main function of passenger … 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
Rodded Unit Weight of Coarse Aggregate Purpose Determination of the unit weight of coarse aggregates in a compacted condition. This test method is applicable to aggregates not exceeding 15 cm (6 inches) in nominal size. The unit weight so determined is necessary for the design of a concrete mixture by the absolute value method. Equipment … Read more