News For This Month: Soils

The Uses and Importance of Aggregates in Construction Aggregates have the important role in giving the necessary strength for concrete. Concrete transitions are the interfacial region between the aggregate and cement paste and this is the one that is responsible in giving compressive strength to the cement. The aggregate should be equiangular and round in size and this must not be irregular and flaky. However, the use of angular aggregates is advised more because such kind of aggregate have a good interlocking effect which have minimum surface area and needs less mortar in covering the surface area. During the extraction time of the aggregates, care must be taken to make the aggregate go sieve analysis or washing before this will be 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. You must consider avoiding using fine sand when it comes to making RCC structures because these are porous and can in fact cause corrosions to the reinforcements.
3 Lessons Learned: Gravel
Fine aggregates have to include natural sand and crushed natural stone and gravel and these must be able to pass through a sieve of opening for about 4.75 mm where the ones that are retained completely are coarse aggregates that would include uncrushed gravel and stone and big boulders.
3 Lessons Learned: Gravel
Aggregates needs to be chemically inert in nature and has to be sufficiently tough, hard and must have good bearing capacity. A well-graded aggregate that is used in a cement mixture is able to help reduce the presence of air voids and it also helps in providing sufficient strength and durability for the concrete. There actually are some tests that are being carried out to some aggregates like abrasion, impact and soundness tests of aggregates that are being done through dissolving it to a certain solution of magnesium and sodium sulphate. In providing support for concrete dams that has a huge mass, aggregates that were formed by igneous rocks has to be used. Though aggregates are usually commonly known as inert fillers in concrete, the different properties of aggregates gives a large impact on durability, strength, workability and also on the economy of concrete. The various properties of aggregates will allow the designers and contractors the flexibility in meeting their design and construction requirements.