#2 concrete mix design and compression tests - Lab Report Example

Concrete quality control is an essential practice to ensure consistency in both the fresh and hardened concrete. Some of the laboratory methods used for concrete quality control include; slump test, compressive strength test and workability tests. The primary objective for this experimental study was to identify the characteristics exhibited by concrete materials and to familiarize with the commonly used laboratory specimen manufacturing and testing methods. In design and quality control of concrete, the most specified concrete property is strength.

This can be attributed to the fact that testing methods available are relatively easy and furthermore; other concrete properties such as resistance to weathering and fire, elastic modulus, and impermeability are directly linked to strength. This means that having the strength data, then the other properties can be deduced. A good concrete mix should take into account the following key attributes: workability, consistency, strength, water cement ratio, durability, density, slump expected, and heat and chemical resistance.

The relative proportions of concrete components, either by volume or weight, will closely influence its properties in both fresh and hardened state. The cement-water paste forms the active component in the concrete material, which is dependent on the characteristics of materials used and their relative proportions. The aggregates used must be well graded to minimize air voids in the concrete matrix. Generally, concrete mix designs are currently being over-designed for the fear of production of results that will not meet the minimum strength criteria specified by the engineer concerned.

There is therefore need for analysis of concrete compressive strength variance and understanding of the criteria for proper concrete mix designs suitable for various applications. Concrete is a