Rock, Stone, the Earth’s perfect building material.
Concrete is also a rock. When properly proportioned with cement or a cementitious material,water, fine, medium and coarse aggregate and properly cured we then shape it back into a rock, but this time a shape that we want it to look like. We build highways, bridges, and structures.
However this new rock, or concrete is heavy and is limited because of it’s composition to protect from heat and cold. It protects us somewhat from the elements: rain, wind, and fire. Rock, stone and concrete are to a degree good insulator but only as a thick or expanded volume.
What if we could find a lightweight building material that has the quality or durability and strength of rock contain freezing - thawing properties, and thermal conductivity as well. How could we achieve this? We would have to change the composition: the weight or density.
One way is to incorporate a lightweight aggregate. Natural lightweight aggregates such as pumice [most widely used], scoria, volcanic cinders, tuff and diatomite. Or artificial aggregates or rotary kiln produced lightweight aggregates such as expanded clays, slates, slag, perlite or shale’s. Cenospheres [hollow sphere comprised largely of silica and alumina with cavities filled of inert gases such as nitrogen and carbon dioxide] and recycled glass beads are additional multi-functional fillers. These low-density aggregates may function well; however they are economically available only in the vicinity of blast furnaces and are becoming increasingly expensive with increased material, fuel and labor costs.
What if we could find a way to lower the density with air? And add a relatively large amount that can be entrained in the concrete without substantially reducing the strength of the ultimate structure. Control the density, control the strengths. This can be done by using a new, improved mechanical air-entraining admixture or concrete containing air cells or voids throughout its volume. A Specified Density Concrete [SDC] called High Strength Lightweight Structural Cellular Concrete or High-Performance Cellular Concrete [HPCC] / Air-Entrained Aggregate Concrete.
