Analysis Of Slump Test

Discussion Slump Test

Two of the slump tests showed true slump in which it just subsides while retaining its overall shape without collapsing. Both of the slumps are within the range of 30mm to 60mm. According to Figure 12, this indicated that degree of workability is medium which makes it suitable for producing normal reinforced concrete. The results also shows that the more water/cement ratio in the mixed concrete, the better the workability as slump increases from 45 to 51mm after extra 200ml of water is added. Curing

Curing allows hydration of concrete to take place as it provides water supply to ensure concrete stays saturated. Under saturated condition, water filled space in concrete could be replaced with cement paste and

This is because the heavier specimens (8.035kg, 8.010kg) are more compacted. However, this difference is negligible because of the mass of the specimen is ± 0.05 to its average mass. For cylinder specimens, on the other hand, the weights are subsequently consistent. Therefore, the results are accepted as the mass of the cylinder specimen is within the ± 0.05 to its average mass.

Compressive stress and Tensile stress testing

It is noted that splitting strength of concrete is very low compared to the compressive strength where Splitting strength only represents about 10% of the compressive strength.

Specimens Splitting Test Results Compressive Test Results cylinder 2.592 19.71 2.643 24.84 3.318 22.51

Figure 16: Splitting test results Vs. Compressive test results for cylinder specimens

The reason for this is that concrete is in triaxial stress state due to friction between concrete and steel platen leads to a higher compressive strength than the actual strength. Effect of end restraint is eliminated in cylinder because it is tested vertically so the compressive strength is closer to unconfined compressive strength compared to cube. From Figure 11, it can be seen that the compressive strength of cube is higher than the compressive strength of

Assuming that each group used equal amount of concrete, the total mass of concrete (2 cubes and 2 cyclinders specimen) for our group is 27.36kg. Compressive vs Tensile Concrete is made from cement, aggregate and water. Interfacial transition zone is the surface between aggregate and cement paste. Concrete is stronger at interfacial transition zone when it moves compressive stress from one aggregate to another when they are pushed towards each other under compression. However, aggregates have difficulty to bind together when it is pulled away from each under tension because the interfacial transition zone takes in all the tensile stress and break easily. Hence, concrete has higher compressive strength compared to tensile strength. Unsatisfactory failure of specimen: Occurrence of unsatisfactory failure of specimen suggested that concrete specimen were not conducted in accordance to the standard required. In order for specimen to have satisfactory failure, the surface area has to be parallel and right angle to the platens on testing machine which may not have been achieved for our group. The specimens may not be placed in exact center in the compressive test machine during concrete testing. Surface of specimens may be uneven due to honeycomb and