Civil Engineering Glossary

The process of selecting suitable ingredients (cement, water, aggregates, admixtures) and determining their relative proportions to produce concrete with specific properties such as workability, strength, and durability.

The ratio of stress to strain within the elastic limit. It measures the stiffness of a material. A higher modulus indicates less deformation under load.

The ratio of the mass of water to the mass of solids in a soil sample, expressed as a percentage. It is a fundamental property affecting soil strength, compressibility, and compaction.

A geometric property of a cross-section that quantifies its resistance to bending. It depends on the shape and distribution of area relative to the neutral axis.

The line within a beam or section where there is no longitudinal stress (neither tension nor compression) when the member is subjected to bending.

A point of known coordinates (easting and northing) used as a reference for establishing other points in a survey network.

Methods used to evaluate the properties of a material, component, or system without causing damage. Common in assessing existing structures.

The volume of excavation beyond the designed theoretical boundary, typically occurring due to blasting effects, unstable rock mass, or excavation equipment overshoot.

A portion of a structural element (like a beam, slab, or roof) that extends beyond its supporting column or wall without direct support underneath.

The most common type of cement, made by grinding clinker (calcium silicates) with a small amount of gypsum. It hydrates with water to form a hard stone-like mass.

The moisture content at which a soil transitions from the semi-solid state to the plastic state. It is the lowest water content at which the soil can be rolled into threads of 3mm diameter without crumbling.

A hydraulic cement produced by intergrinding OPC clinker with pozzolanic materials (fly ash, volcanic ash) and gypsum. It gains strength slower but has better durability.

A failure mode in flat slabs or footings where a concentrated load (like a column) punches through the slab, creating a conical failure surface around the column.

The measure of the ability of a soil to allow water to flow through its voids under a hydraulic gradient.

A method of reinforcing concrete where internal stresses are introduced to counteract the tensile stresses developed by external loads. High-strength steel tendons are tensioned before or after casting.

A metamorphic rock formed from sandstone, consisting primarily of quartz grains. It is extremely hard, durable, and resistant to weathering, making it an excellent coarse aggregate for high-strength concrete.

QA: Process-oriented activities to ensure the processes used to create the product are correct (prevention of defects).
QC: Product-oriented activities to detect defects in the final product (inspection, testing).

A condition in cohesionless soil (sand) where the upward flow of water creates a seepage force equal to the submerged weight of the soil particles, causing the soil to lose shear strength and behave like a liquid.

The resisting forces exerted by supports on a structure to maintain equilibrium. Reactions balance the external loads applied to the structure.

Steel bars (rebar) embedded in concrete to carry tensile stresses, which concrete cannot resist effectively. Provides ductility and strength to the composite member.

A composite material where concrete carries compressive stress and steel reinforcement carries tensile stress. The bond between steel and concrete ensures they act together.

A structure designed to hold back soil or rock from collapsing. It resists lateral earth pressure (active pressure) and prevents landslides or erosion.

The layer of granular material placed immediately below the sub-base or directly above the sub-grade in flexible pavements. It distributes loads from the surface course to the sub-grade.

An index number expressing the relative compactness of cohesionless soils (sand/gravel). It compares the natural void ratio to the maximum and minimum void ratios.

A large continuous slab that supports multiple columns and walls simultaneously, covering the entire area of the structure. It acts like a raft floating on the soil.

The portion of precipitation that flows over the land surface towards streams, rivers, or reservoirs instead of infiltrating into the ground or evaporating.