structural Engineering

Extensive green roofs are designed to be lighter in weight, relatively cheap, not open to recreational use and requiring the minimum of maintenance. Their prime purpose is either ecological or for the environmental masking of buildings. Planting should be of drought-tolerant, wind- and frost-resistant species, such as sedums, herbs and grasses. Instant cover can becreated […]

Single-ply roofing systems consist of a continuous membrane usually between 1 and 3 mm thick, covering any form of flat or pitched roof As water – proofing is reliant on the single membrane, a high quality of workmanship is required, which is normally provided by the specialist installer. In refurbishment work where the substrate may

Ferrous metals are defined as those in which the element iron predominates. The earliest use of the metal was for the manufacture of implements and weapons in the Iron Age commencing in Europe circa1200 BC. Significant developments were the use by Wren in 1675 of a wrought iron chain in tension to restrain the outward

Concrete is strong in compression, with crushing strengths typically in the range 20–40 MPa, and up to 100 MPa for high-strength concretes. However, the tensile strength of concrete is usually only 10% of the compressive strength. Steel is the universally accepted reinforcing material, as it is strong in tension, forms a good bond and has

Thermal movement The coefficient of thermal expansion of concrete varies between (7 and 14) X 10–6 °C, according to the type of aggregate used, the mix proportions and curing conditions. Moisture movement During the curing process, concrete exhibits some irreversible shrinkage which must be accommodated within the construction joints. The extent of the shrinkage is

To maintain quality control of concrete, representative test samples should be taken, cured under controlled conditions and tested for compressive strength after the appropriate 3- , 7- or 28-day period. Steel cylinder and cube moulds are filled in layers with either hand or mechanical vibration. For hand tamping, a 100 mm cube would be filled

Portland cement mortar is unnecessarily strong and concentrates any differential movement within brick -work or blockwork into a few large cracks, which are unsightly and may increase the risk of rain penetration.Masonry cement produces a weaker mortar, which accommodates some differential movement, and ensures a distribution of hairline cracks within joints, thus preserving the integrity

Cements are classified primarily on the type of the main constituents such as Portland cement or blast furnace cement. (In addition, there may be minor constituents up to 5% and also additives up to 1% by weight.) The standard BS EN 197–1: 2011 lists five main types of cement: CEM I Portland cementCEM II Portland-composite

Beam and block flooring is the standard alternative to floating ground floors within domestic-scale construction , and may also be used for upper storeys. Systems are described in BS EN 15037. Beams may be inverted T or I in form, or alternatively incorporate partially exposed lattice girder reinforcement to be incorporated within a concrete topping

Concrete blocks (masonry units) are defined as solid, cellular or hollow. Concrete blocks are manufactured to various work face dimensions in an extensive range of widths, offering a wide choice of load-bearing capacity and level of insulation. Manufacturer’s work size dimensions should be indicated as length, width and height, in that order, to BS EN