Home / concrete

concrete

CREEP And SHRINKAGE OF CONCRETE

CREEP A phenomenon which affects most materials to some extent is that of creep, or timedependentdeformation under constant load. Creep is particularly important in concrete, and affects both the long-term deflections and loss of prestress force in prestressed concrete members. The basic mechanism of creep in concrete is that of …

Read More »

STRENGTH OF CONCRETE

The strength of concrete is primarily affected by the water/cement ratio, that is the ratio of the weights of mixing water and cement used in a mix. The lower the water/cement ratio the higher the strength, and typical relationships between water/cement ratio and compressive cylinder strength at different ages. A …

Read More »

MIXING Concrete

MIXING Concrete must be mixed so the Cement, Water, Aggregates and Admixtures blend into an even mix. Concrete is normally mixed by MACHINE. Machine mixing can be done on-site or be a Pre-Mixed concrete company. Pre-Mixed concrete is batched (proportioned) at the plant to the job requirements. Truck Mixing The …

Read More »

Ordering Concrete

WHEN ORDERING PRE-MIXED concrete you will need to tell the supplier:Name and address for delivery The use of the concrete (ie driveway, housing slab, commercial)The amount you need in cubic metres The Class of the concrete. There are two classes that concrete can be supplied as: Normal Class and Special …

Read More »

THE COMPRESSION TEST

The compression test shows the compressive strength of hardened concrete. The testing is done in a laboratory off-site. The only work done on-site is to make a concrete cylinder for the compression test. The strength is measured in Megapascals (MPa) and is commonly specified as a characteristic strength of concrete …

Read More »

Concrete Testing

There are two main tests to be done on concrete: The SLUMP test. The SLUMP test shows the WORKABILITY of concrete. Workability measures how easy the concrete is to place, handle and compact. The COMPRESSION test. The COMPRESSION test shows the best possible strength concrete can reach in perfect conditions. …

Read More »

Concrete Properties

The Properties of Concrete are its characteristics or basic qualities. The four main properties of concrete are: WORKABILITY COHESIVENESS STRENGTH and DURABILITY Concrete has three different states PLASTIC SETTING HARDENING CONCRETE STATES Plastic State  When the concrete is first mixed it is like ‘bread dough’. It is soft and can …

Read More »