Lightweight Concrete for High Strength - Expanded Shale & Clay

Variation of coarse-to-fine aggregate ratio (Figure 3.3) and silica fume content (Figure 3.4) gave
optimum results of 1.5 and 10% respectively.
12,000
Compressive Strength (psi)
11,000
10,000
9,000
8,000
7,000
1 Day Strength
6,000
28 Day Strength
0.9 1.1 1.3 1.5 1.7 1.9
Coarse-to-Fine Ratio
Figure 3.3 1 Day Strength and 28 Day Strength Results for 1/2-in. Aggregate at Varying Coarseto-Fine
Ratios
11,000
Compressive Strength (psi)
10,500
10,000
9,500
9,000
8,500
8,000
1 Day Strength
28 Day Strength
2 4 6 8 10 12 14
Silica Fume Percentage by Weight
Figure 3.4 1 Day and 28 Day Strengths with Varying Silica Fume Contents
3-3