WHAT ARE THE FACTORS INFLUENCING COMPRESSIVE STRENGTH TEST RESULTS OF CONCRETE?

Correction factor for height-diameter ratio of a core

Factors Affecting Strength Test Results of Concrete Compressive strength is the most important property of concrete. The compressive strength of concrete is determined in the laboratory in controlled conditions. On the basis of this test result we judge the quality of concrete. But sometimes the strength test results vary so widely that it becomes difficult … Read more

HOW TO CAP CONCRETE CYLINDERS? (4 METHODS OF CAPPING)

Capping mould with fix bar

Capping of Concrete Cylinders Capping is required to give a smooth surface for applying compressive load to concrete cylinders. Only cylindrical concrete test specimens are capped using appropriate method. When the ends of cylindrical test specimens are not plane within 0.05 mm, it is required to cap those test specimens. The capped surfaces should be … Read more

HOW TO CALCULATE SAFE BEARING CAPACITY OF SOIL ON SITE?

How to calculate safe bearing capacity of soil on site

This simple and quick field test will give you a rough idea of bearing capacity of soil. Procedure Excavate a pit of required depth. (preferably equal to the depth of foundation) Take a solid ball or square cube of known weight and dimension. Drop the ball or square cube several times, from a known height … Read more

WHAT ARE THE ADVANTAGES OF PPC (PORTLAND POZZOLANA CEMENT)

Advantages of PPC (Portland Pozzolana Cement)

Advantages of PPC in Fresh Concrete Portland pozzolana cement (PPC) has following advantages when concrete is in its fresh state. 1. Workability Portland pozzolana cement has spherical cement particles and they have higher fineness value. Due to the spherical shape concrete move more freely and more fineness of particles allows better filling of the pores. … Read more

HOW TO FIND VOLUME OF CONCRETE PER BATCH?

volume of concrete per batch

Aim To determine volume of concrete per batch, where nominal maximum size of aggregate does not exceed 38 mm. Apparatus Balance – Sensitive to 0.01 kg Tamping bar – Length 38 cm, Weight 1.8 kg Cylindrical mould – Dia = 250 mm, Height = 280 mm, Capacity = 0.01m3 Step by Step Procedure to Calculate … Read more

HOW TO IMPROVE BEARING CAPACITY OF SOIL?

How to improve bearing capacity of soil

Techniques Used for Improving Bearing Capacity of Soil The following techniques can be used for improving bearing capacity of soil as per the site condition. Increasing depth of foundation Draining the soil Compacting the soil Confining the soil Replacing the poor soil Using grouting material Stabilizing the soil with chemicals 1. Increasing Depth of Foundation … Read more

WHAT ARE THE FACTORS AFFECTING FIELD COMPACTION OF SOIL?

There are many factors which influence the degree of compaction in the field. Some are compactor dependent and some depend on the soil being compacted. The factors which affect the degree of compaction are given below. 1. Type of soil Type of soil has a great influence on its compaction characteristics. Normally, heavy clays, clays … Read more

HOW TO DETERMINE SPECIFIC GRAVITY OF SOIL?

Objective For determination of specific gravity of soil solids by pycnometer method. Equipment & Apparatus Pycnometer Sieve(4.75 mm) Vacuum pump Oven Weighing balance Glass rod Preparation sample After receiving the soil sample it is dried in oven at a temperature of 105 to 1150C for a period of 16 to 24 hours. Procedure Dry the … Read more

HOW TO INSPECT PHYSICAL CHARACTERISTICS OF AGGREGATE USED IN CONCRETE?

While inspecting aggregate for quality control purpose, it is required to describe its physical properties, because physical properties of aggregate have an effect on the property of concrete. The physical properties of aggregate which should be described are given below. Name of parent rock & Group name Particle Shape Surface Texture Let us see how … Read more