Construction Aggregates: How Important are They?
Aggregates are very important because it supplies the needed strength for concrete. The transition of concrete would be the interfacial region between the cement paste and aggregate and is the one that’s responsible in providing compressive strength to the cement.
Aggregates must be round and equiangular in size and must never be irregular and flaky. But, the use of angular aggregates is highly advised because these kind of aggregates comes with good interlocking effects, having minimum surface area and will less mortar in covering the surface.
During the time of extraction of the aggregate, care should be considered to make the aggregate undergo washing or go through sieve analysis before this is used. The presence of harmful materials involving silt, clay or acidic salts can in fact affect the strength and durability of concrete that could potentially lead to inhomogeneity in composition and to the failure of the structure when subjected to eccentric loading. There are some associations that specifies four grading zones for fine aggregates that are placed in order for decreasing particle size that starts from coarse sand and ending with fine sand. It is best that you don’t use fine sand in making RCC structures because they are porous and could cause corrosions in the reinforcement.
News For This Month: Sand
Fine aggregates will include natural sand, crushed natural stone and crushed and these particles must be able to pass through a sieve opening for about 4.75 mm and the ones that are completely retained are coarse aggregates that includes uncrushed gravel and stone and the big boulders.
The Art of Mastering Sand
Aggregates must be inert chemically in nature and has to be tough sufficiently, hard and should possess good bearing capacities.
Aggregates that are well-graded and used in a cement mixture helps to reduce the presence of air voids and also helps in providing sufficient strength and durability to the concrete.
There are some tests which are carried out to some aggregates like impact tests, abrasion tests and soundness tests of aggregates that are done through dissolving them in a certain solution of sodium and magnesium sulphate.
To provide the necessary support for concrete dams which has a huge mass, aggregates which were formed by igneous rocks are the ones that are preferred highly.
Even when aggregates are commonly known as inert fillers in concrete, various properties of aggregates are able to give a large impact when it comes to durability, strength, workability and on the economy of concrete. The different properties of aggregates will allow designers and contractors with the most flexible option to meet their design and construction requirements.