NON-DESTRUCTIVE TESTING CONCRETE

Rebound hammer test  The rebound hammer or Schmidt hammer (Figure 43) gives a comparative measure of concrete quality as indicated by s...

TEST CORES QUALITY OF HARDENED CONCRETE

Core tests are useful for assessing the quality of hardened concrete in site. Not only can the comprehensive strength of the concrete b...

TESTING FRESH CONCRETE

The measurement of the consistence of fresh concrete is of importance in assessing the practicability of placing and compacting it and...

TESTING MATERIALS CEMENT AGGREGATES CLEANNESS

Cement  The testing of cement is done in accordance with the standard procedures in BS EN 196, which is published in different parts ...

TESTING CONCRETE & CONCRETING MATERIALS

Most tests on concrete and concreting materials fall into one of the following categories: 1. Tests, carried out mainly in a laborat...

FLOOR FINISHES GOOD-QUALITY CONCRETE

A good-quality concrete, well laid and finished makes a satisfactory floor for many purposes. The concrete surface can be smooth, easil...

CONCRETE FOR HIGH QUALITY FINISHES

In order to be able to control the quality of the concrete to the standard required for visual concrete, it is essential to have the co...

CONCRETE SURFACE FINISHES

Visual concrete, which is designed to be seen in a completed building or structure, requires special consideration at an early stage, s...

MINIMUM PERIODS OF CURING AND PROTECTION CONCRETE

Curing is the process of preventing the loss of moisture from the concrete while maintaining a satisfactory temperature regime.  The ...

FORMWORK CONTAIN FRESHLY PLACED AND COMPACTED CONCRETE

The purpose of formwork is to contain freshly placed and compacted concrete until it has gained enough strength to be self- supporting; ...

REINFORCEMENT CONCRETE

Reinforcement for concrete may consist of round or deformed steel bars or welded steel mesh fabric. These materials are covered by BS 4...

CONCRETING IN HOT WEATHER

In the UK when temperatures exceed about 20°C, there are two main factors leading to problems with concreting: n When the tempe...

CONCRETING IN COLD WEATHER

It is well known that water expands when it freezes. This can cause permanent damage and disruption if freezing is allowed to occur wit...

CONSTRUCTION AND EXPANSION JOINTS

A construction joint, or day-work joint, is one where fresh concrete has to be placed on or against concrete that has already hardened. ...

PLACING & COMPACTION OF CONCRETE

The successful placing and compaction of concrete can be achieved only if there has been careful forethought and planning.  Because they ar...

METHODS FOR TRANSPORTING CONCRETE

A number of methods for transporting concrete on site are available, ranging from hand wheelbarrows to concrete pumps. The choice of ...

SITE BATCHING & MIXING

Although most concrete nowadays is delivered ready-mixed, there may be occasions when it is more economic and practicable for the concret...

READY-MIXED CONCRETE

About three-quarters of all concrete placed on site in the UK is supplied ready-mixed. To ensure ready-mixed concrete is used successfull...

EFFECT OF CONCRETE CONSTITUENTS

Cement The effects of different types of cement have already been described in the section on Cements. Within one type the propertie...

STANDARDIZED PRESCRIBED CONCRETES

Whilst strength testing is not intended to be used to judge conformity for standard or standardized prescribed concrete, the characteristi...