Civil engineering

Civil engineering

1. How did the workability vary from your group’s plain concrete results and explain why?

The workability of concrete shows how freshly mixed concrete can be placed, combined, consolidated, and finished with little loss of homogeneity. The workability varied from 0 – 1.68 mm, thus making the force to fluctuate between 18388.4 N and 244753 N. The workability varies due to the different shapes that the slump forms after the cone slump has been removed. These shapes include true slump, zero slumps, collapsed slump, and sheer slump.

The workability of the concentrates under test could also be affected by water content, cement concentration, and sand. However, it can also be affected by aggregate properties such as size, shape, mix design ratio, grading, and admixture use. Additionally, the processes followed, and the component materials involved in the concrete mix also affects the workability results of a concrete.

1. How did your cube compressive strength vary from your other group’s results and suggest why?

Comprehensive strength is the ability of a material or concrete to withstand or resist when subjected to compression. Therefore, to determine the compressive strength, one needs to assess the ability of a material to resist failure about cracks and flexure. Group 2 compressive strength was the highest while others are falling below the 24.5 MPa, which recorded Group 2 compressive concrete strength. The cube compressive strength is also high above the mean strength of 18.5 MPa. With the average at 18.5 MPa, this means that most group results were about 18.5MPa with a deviation of about + or – 1 MPa.

The reason for the high comprehensive strength is due to the upper force that was applied to the cube of 244.75N. The variation in cube compressive strength varies because the values gotten depend on the number of aggregates, voids, and volumes of the cement products under test. The surface of the cube needs also to be smooth to distribute the load pressure uniformly.

2. How did the compressive stress in the concrete at failure in flexure compare to the cube compressive strength? What does this imply?

The compressive stress at failure is more than the compressive strength. The compressive stress at failure is 24.5MPa, while cube compressive strength is 6.4 MPa at 20 degrees Celsius. This implies that when the cube is subjected to more than 6.4 MPa force at 20 degrees Celsius the cube will be crack or flexure.

3. List five ways in which the load which this beam carries could be improved
4. One needs to figure out the type of place the construction is to take place and the highest possible force that needs to be applied, which, therefore, guides in strengthening the zones by constructing a bigger cross-sectional surface.
5. Increasing the bending moment strengths of the cross-sectional area, which raises the ability of the beam to carry more load, thus resisting bending moments.
6. Achieving full plasticity around the central section, thus having other positions on either side of the center distance for support purposes, thus making the beam to be an elastic-plastic state.
7. The engineer needs to calculate the load to collapse, then the safety factor to determine the amount of weight that can be added for the beam to collapse.
8. Lowering the center of gravity or centroid can also help in increasing the amount of load the beam can carry.

References

Hearn, E. J. (1997). Mechanics of Materials 2 an Introduction to the Mechanics of Elastic and Plastic Deformation of Solids and Structural Materials (Third, Vol. 2).

The Constructor – Civil Engineering Home. (2017, November 30). What are the Factors Affecting Workability of Concrete? Retrieved December 4, 2019, from https://theconstructor.org/concrete/factors-affecting-workability-concrete/11190/.