No-Fines Concrete

concrete produced from a mix of solid or porous (mainly uniform-fraction) gravel or crushed stone, a binder (portland cement or slag portland cement), and water. The absence of sand in the mix and the limited consumption of cement (not more than 280 kg/m³) account for the honeycomb structure of the concrete, the reduced density, and the low heat conduction. The compressive strength of concrete with solid fillers does not exceed 10 meganewtons per sq m (MN/m²), or 100 kilograms-force per sq cm (kgf/cm²), at a density of up to 2,000 kg/m³; for concrete with porous fillers it is 7.5 MN/m² (75 kgf/cm²) at a density of up to 1,600 kg/m³. The heat conduction is 0.29-0.9 watts per m per degree Kelvin, or 0.25-0.85 kcal per (meter per hour per degree Centigrade).

No-fines concrete is used mainly for erecting cast or large-block exterior walls of buildings in regions rich in local gravel or rock for crushed rock in the absence of other inexpensive wall materials. Walls made from this type of concrete are plastered on both sides to prevent air drafts. No-fines concrete made from a porous filler (keramzit gravel or sifted slag) is also used as an insulating material in the sandwich enclosing structures of buildings.