7 FACTORS INFLUENCING REBOUND HAMMER TEST OF CONCRETE

7 Factors Influencing Rebound hammer test of concrete

Rebound Hammer Test The Schmidt rebound hammer is principally a surface hardness tester with little apparent theoretical relationship between the strength of concrete and the rebound number of the hammer. However, within limits, empirical correlations have been established between strength properties and the rebound number. Further, scientist has attempted to establish a correlation between the … Read more

BULKING OF FINE AGGREGATE – WHAT, WHY & HOW?

Field test on sand

Bulking of Sand – What, Why & How? After watching this video you will be able to answer following questions. What is bulking of sand? Why bulking happens? What are the factors affecting bulking of sand? How to measure bulking of sand at site? What are the effects of bulking on concrete? How to apply … Read more

HOW TO CHECK SUITABILITY OF WATER FOR CONCRETE MIXING?

How to check quality of drinking water

SUITABILITY OF WATER FOR CONCRETE MIXING OBJECTIVE To assess suitability of water for use in concrete mix. Equipment Measuring cylinder Cube moulds Trowel Tamping rod Vibrating table Testing machine Procedure Analyse water for its chemical compositions as per IS 3025-1964 and compare these with permissible limits given in IS: 456-2000. In case water does not … Read more

HOW TO DO FLEXURAL STRENGTH TEST OF CONCRETE?

Flexural Strength Test Arrangement

FLEXURAL STRENGTH TEST OF CONCRETE Objective To determine the Flexural Strength of Concrete, which comes into play when a road slab with inadequate sub-grade support is subjected to wheel loads and / or there are volume changes due to temperature / shrinking. Reference Standards IS: 516-1959 – Methods of tests for strength of concrete Equipment & … Read more

3 METHODS OF DETERMINING WORKABILITY OF CONCRETE

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

FLEXURAL STRENGTH TEST OF CONCRETE (IS:516-1959)

Flexural Strength Test Arrangement

Objective To determine the Flexural Strength of Concrete, which comes into play when a road slab with inadequate sub-grade support is subjected to wheel loads and / or there are volume changes due to temperature / shrinking.  Reference Standards IS: 516-1959 – Methods of tests for strength of concrete Equipment & Apparatus Beam mould of size … Read more

HOW TO DETERMINE OF BOND STRENGTH BETWEEN STEEL & CONCRETE? [PULL OUT TEST]

APPARATUS FOR BOND STRENGTH TEST

Theory The bond strength is the measure of the effectiveness of the grip between concrete and steel and has no standard quantitative definition. In pull out tests on plain bars, the maximum load generally represents the bond strength that can be developed between concrete and steel. With plain bars the maximum load is not very … Read more

SLUMP TEST OF FRESH CONCRETE TO MEASURE WORKABILITY (IS-1199-1959)

Slump test of concrete to measure workability

Slump Cone Test of Fresh Concrete Object This test is performed to measure consistency or workability of fresh concrete, where the nominal maximum size of aggregate does not exceed 38 mm using slump test apparatus. Reference Standards IS : 1199 – 1959 – Method of sampling and analysis of concrete. Equipment & Apparatus Slump cone (Height … Read more

HOW TO DETERMINE DRYING SHRINKAGE OF HARDENED CONCRETE?

Length Comparator for measuring initial drying shrinkage of concrete specimen

Aim This test method describes the procedure for determining the drying shrinkage or change in length of concrete specimen due to changes in moisture content. Apparatus A length measuring apparatus incorporating a dial gauge capable of measuring the length accurately to 0.005 mm. (see fig shown below) Drying oven capable of maintaining a temperature of … Read more

WHAT IS NON-DESTRUCTIVE TESTING OF CONCRETE & VARIOUS NDT TEST METHODS?

NDT test on concrete

Non-Destructive Testing of Concrete (NDT on Concrete) Non destructive test is a method of testing existing concrete structures to assess the strength and durability of concrete structure. In the non destructive method of testing, without loading the specimen to failure (i.e. without destructing the concrete) we can measure strength of concrete. Now days this method … Read more