CEMENT STABILISED MATERIALS

Cement Stabilised Materials

Cement Stabilised Materials

Introduction

Since most developing countries lie in the tropics or sub-tropics the differences between pavement engineering in temperate industriafised countries and developing countries are often thought of almost exclusively in terms of climatic differences. While these differences are substantial, a considerable body of knowledge exists that enables experienced designers to incorporate reasonably satisfactory provisions within their designs for all but the most extreme effects of tropical climates.

Equally important differences between pavement engineering in developing and industrialised countries are the greater variabfity of construction materials, quality of construction, and the larger fluctuations in the volume and weight of road traffic that are typically encountered in developing countries. .

Cement Stabilised Material

Soil Cement

Soil cement is a construction material, a mixture of pulverized natural soil with small amount of portland cement and water, usually processed in a fall, compacted to high density. Hard, semi-rigid durable material is formed by the hydration of cement particles.

Soil cement is frequently used as construction material for pipe bedding, slope protection and road construction as a subbase layer of reinforcement and protection of the subgrade. It has good resistance to compression and shear, but low tensile strength and fragility, making it prone to cracking. (Pell 1978)

While in Portland cement concrete paste all layers of aggregate particles and binds them together, in the amount of soil cement cement is lower and therefore there are gaps on the left and the result is a cement matrix with nodules uncemented material.

Once the concrete floor contains relatively small proportion of Portland cement. The result is slightly hardened or hardened material, similar to a floor, but with improved mechanical properties - less plasticity, taking a greater proportion and the cutting force and decrease the volume change. A soil-cement base contains higher proportion of cement modified cement floor. It is commonly used as an economic base for paving roads, streets, parking lots, airports and material handling areas. Specialized equipment, such as a soil stabilizer and cement mechanical separator is usually necessary. A seal coat is needed to maintain moisture. For use as road construction material, a suitable surface coating, typically a thin layer of asphalt concrete, is necessary to reduce wear.

Compared with granular base, soil cement bases may be thinner same road load, due to its layer-like behavior that spreads the load over wider areas. On site or near materials located may be used for construction - found local soil, stone, or reclaimed granular base of a road under reconstruction. This conserves materials and energy. The strength of the soil cement bases increases with age, providing good long-term performance.

Unbound Granular Materials

DTP Type 1 Granular Sub-Base

The name refers to DOT specifications. The full title is "Type 1 granular sub-base for the Department of Transport Specification for Highway Works" It is still called MOT1 (the former Ministry of Transport) or even the most inaccurate "40mm to dust." In Ireland it is commonly known as "803", a name derived from the fact that the complete specification is in section 803 of the Roads Specification ...