Table of Contents
- 1 What is the effect of coarse aggregate size in compressive strength of concrete?
- 2 How does the increase of maximum aggregate size used in the concrete mix design affect the percentage of fine aggregates needed for the mix explain why this is the case?
- 3 What is the effect of water cement ratio on strength and durability of concrete?
- 4 What is the difference between crushed and uncrushed aggregates?
- 5 How to design concrete mix for a specific grade?
- 6 What is the difference between concrete mix and aggregate mix?
What is the effect of coarse aggregate size in compressive strength of concrete?
strengths than the larger sized coarse aggregate. Cook observed that the difference in compressive strengths due to aggregate size is increasingly larger with a decreasing water-to-cement ratio and increasing test age. The smaller sized coarse aggregate also increases the flexural strength of the concrete.
How does the increase of maximum aggregate size used in the concrete mix design affect the percentage of fine aggregates needed for the mix explain why this is the case?
Higher the surface area, greater is the water demand to coat the particles and generate workability. Smaller maximum size of coarse aggregate would require greater fine aggregate content to coat particles and maintain cohesiveness of concrete mix.
Does larger aggregate make concrete stronger?
At a given water ratio, within the range employed in most structural concrete, smaller maximum sizes of aggregate will tend to produce higher concrete strengths than larger ones.
What is the effect of maximum size of aggregate on concrete strength?
A. As the nominal maximum size of the aggregate is increased, the amount of water needed for the same workability is reduced. At the same cementitious material content, strength is therefore greater because the w/cm is lower.
What is the effect of water cement ratio on strength and durability of concrete?
If the water-cement proportion is higher, it brings about wider spacing between the cement aggregates and thus, influences the compaction. Correspondingly, concrete’s durability and compressive strength are decreased due to increased dampness levels.
What is the difference between crushed and uncrushed aggregates?
Relevant to mention: uncrushed aggregate is cheaper than crushed aggregate. Consequently, concrete with uncrushed aggregates will be cheaper. It can be concluded that uncrushed aggregates are appropriate for medium grade concrete for better performance in terms of workability, strength and economy.
What is the difference between crushed and uncrushed aggregate?
What is the effect of aggregate size on the mix design?
It is reported that, high maximum coarse aggregate size leads to lower water demand in the mixture since such aggregate has lower surface area compare with small coarse aggregate size. As far as shape is concerned, rounded shape aggregate provides economical mix design for normal strength concrete.
How to design concrete mix for a specific grade?
Design of concrete mix for a particular grade of concrete involves proper selection of relative proportions of cement, sand, and coarse aggregates. While designing a concrete mix, it is always tried to obtain a minimum strength which is equal to characteristic strength of concrete but concrete must have the desired workability and durability.
What is the difference between concrete mix and aggregate mix?
Hence the mix is cohesive and avoids segregation. The shape and texture of aggregate affects the properties of fresh concrete more than hardened concrete. Concrete is more workable when smooth and rounded aggregate is used instead of rough angular or elongated aggregate.
What is the importance of Fine and coarse aggregate in concrete?
The relative proportions of the fine and coarse aggregates in a concrete mix are one of the important factors affecting the workability and strength of concrete. For dense concrete it is essential that the coarse and fine aggregates be well graded, giving the maximum packing density.