Cementsand

Cementsand, commonly called cement-sand mortar, is a binding material used in masonry and plastering. It is formed by mixing Portland cement with fine sand and water. When hydrated, the cement binds the sand particles to create a solid, workable matrix that adheres to bricks, blocks, or stone.

Typical ratios by volume vary with application. General masonry mortar is often 1 part cement to 3 parts sand; plaster or screed mixes can be 1:4 or 1:5. Sand quality greatly affects performance; clean, well-graded, and washed sand is preferred. Some formulations include lime to improve workability and vapor permeability, especially for traditional or historic work.

Common uses include laying bricks or blocks, pointing joints, plastering walls, and bedding floor tiles or pavers. Cement-sand is distinct from concrete, which includes coarse aggregates. Variants include cement-sand-plaster and cement-lime-sand mortars, chosen for required strength, flexibility, or compatibility with existing substrates.

Curing and performance depend on moisture. Initial set occurs within hours, with increasing strength over 28 days under proper curing. Inadequate curing or excessive water can cause cracking and reduced bond. Handling should be done on clean surfaces; mix thoroughly, and store bags properly to avoid moisture.

Environmental considerations include the carbon footprint of cement production. Reducing cement content with supplementary cementitious materials or lime, and using recycled aggregates, can mitigate impacts.