Did you know?
Cement & Concrete SA offers a free advisory service for general concrete technology queries.
A consultancy service focused on concrete and related issues are offered, including on-site investigation, troubleshooting and reporting. The technical team is available for consultation on construction sites anywhere in Southern Africa.
Leaflet Sections
Cement
Cementitious materials for concrete: standards, selection and properties
Provides information on the standards that apply in South Africa to cementitious materials for concrete. Guidance is given on selection for various applications, includes graphs of strength performance, and discusses, briefly, the manufacture and properties of cementitious materials and fillers. The cementitious materials dealt with are all based on portland cement and many contain a “cement extender”. Masonry cements are outside the scope of this leaflet since they are not intended for use in concrete.
Concrete Mixes
Concrete, plaster and mortar mixes for builders
Presented largely in graphic form, this practical leaflet gives the proportions for large and small batches of concrete, mortar and plaster. It includes brief guidelines on quantities of materials to order.
Mortar mixes for masonry
Mortar binds bricks and blocks together to give strength and stability to a wall. The leaflet discusses briefly the required materials and mix proportions to give freshly mixed mortars the necessary softness and plasticity. It also covers batching, mixing and handling the mortar as well as quantities of materials to order for mortar mixes per cubic metre or per 50 kg bag of cement.
Quantities for ordering building materials
Approximate quantities of materials required are given for: concrete; masonry walling; mortars, plasters and floor screeds.
Trial concrete mixes: proportions and quantities for ordering
Trial mix proportions for concrete made with four stone sizes and with strengths ranging from 10 MPa to 40 MPa are presented in tabular form. A field test for assessing and adjusting stone content is also given.
Concrete Technology
Admixtures for concrete
Admixtures are chemicals which are added to concrete at the mixing stage to modify some of the properties of the mix. The leaflet covers the most common reasons to use admixtures and looks, in some detail, at the five types most commonly used in construction. The properties, dosage, uses and practical considerations for each type are discussed. Advice is also given on the design of mixes, storage and handling, dosage and dispensing of admixtures.
Fibre-reinforced concrete
While concrete made with portland cement is strong in compression, it tends to be weak in tension and can also be brittle. The weakness in tension can be overcome by the use of conventional rod reinforcement and by the inclusion of sufficient volumes of certain fibres. This leaflet looks briefly at the concept of toughness, the use of fibres and the types of fibre and their properties.
Foamed concrete
Foamed cement is a lightweight concrete which normally has a density of between 400 and 1 600 kg/m3 (compared with about 2 300 kg/m3 for ordinary concrete). It is made of a cementitious material, a filler or aggregate and an aerated foam. Intended to give an appreciation of the material rather than offering a method of manufacture, this leaflet briefly discusses materials for foamed concrete, how it is produced, its properties and typical applications.
Monitoring concrete strength by the cusum system
The production of concrete must be controlled in such a way that strength specifications are met and materials costs are kept as low as possible. The cusum system is a practical means of meeting these requirements. This technical guide, intended for concrete producers and readymix plant operators, deals mainly with monitoring the strength of a single grade of concrete (using a single set of materials) by the cusum system. Combining (or massing) results from several mixes into one cusum is dealt with briefly.
No-fines concrete: a practical guide
No-fines concrete (NFC) consists of coarse aggregate and cement paste. It has large interconnected voids and a much lower density than conventional concrete. Its structure makes it ideal for use as a drainage layer under reservoir and basement floors, as an insulating layer and as a damp-proofing material. Information in the leaflet includes materials and mix proportions, manufacture, placing and compacting, protection, curing and screeding NFC.
Tests on concrete
This leaflet has been prepared to assist the operator and describes, step by step, the procedures for carrying out the following tests: how to measure slump and how to make 150 mm cubes. The titles of the applicable SABS methods of test are given in the list of references.
Farm Projects
Concrete at home and on the farm
There are many small concrete projects which the home-owner can confidently tackle. This is a practical guide to making concrete for small jobs and covers the materials needed, how thick the concrete should be, how much is required, suggested mix proportions and how to go about mixing, placing and curing the concrete.
Concrete strip roads for the farm
Economical and durable all-weather roads, especially suitable for farms and rural areas, can be made with concrete strips laid as wheel-tracks. They can be built without expensive or sophisticated equipment and work can be done in short lengths as labour is available. Strip roads are a particularly useful means of making steep farm roads passable in all weather condition.
Floors and Pavements
Repairing spalled joints in concrete floors
Gives guidance on the repair of spalled joints in concrete floors using portland cement concrete.
Sand-cement floor screeds and concrete toppings for floors
Sand-cement screeds and concrete toppings commonly used as a means of providing a smooth flat floor surface. The moderately theoretical and technical publication aims to provide the information needed by architects, engineers and contractors to specify and lay floor screeds and acceptable quality.
Health and Safety
Guide to the safe use of portland cements and concrete
Concrete is the world’s most widely used building material and workers in every construction sector, as well as DIY enthusiasts, handle cement and wet concrete every day. Like all materials, there are potential risks involved in handling cement and concrete. This leaflet identifies the areas of risk, provides guidance on how to avoid unprotected exposure, and outlines basic first aid procedures.
Home and Garden Projects
Building a fish pond
Covering the construction of a pond shell in concrete, the method described is suitable for ponds with a diameter or length of up to 5 metres. The leaflet provides notes on excavating, lining the excavation, manufacture and use of spacer blocks, mesh reinforcement and mixing and placing the concrete. Water circulation and filtration are not included, and it is strongly recommended that the reader obtain specialist advice on this aspect.
Building a pizza oven
This leaflet gives guidance on the selection of materials as well as providing step-by-step instructions on how to construct a pizza oven for home use. It also includes a simple and practical method for supporting the dome during building.
Concrete for precasting small items
Precasting is an economical means of producing high-quality concrete items. This leaflet gives information for small-scale precasting of relatively small unreinforced or reinforced items such as paving slabs, planks and elements for post-and-panel walling. It covers: choice of materials; mix proportions; and manufacturing processes including batching, mixing, transporting, placing, protecting, demoulding and curing.
Lay a concrete driveway at home
A well-laid concrete driveway will give at least 20 to 30 years’ trouble-free service and can be laid quite easily by the ordinary homeowner. This publication describes briefly the preparation of the site, recommended concrete mixes, placing of the concrete, jointing and curing.
Making small garden ornaments in concrete
Explains how to produce garden ornaments weighing about 40 kg and manually movable by one person. The leaflet describes the equipment and materials required, how to prepare the pattern and make the mould as well as the steps involved in casting, demoulding and curing the ornament. In addition, guidance is given on how to colour the concrete and repair it if necessary.
Making small garden ornaments in concrete
Explains how to produce garden ornaments weighing about 40 kg and manually movable by one person. The leaflet describes the equipment and materials required, how to prepare the pattern and make the mould as well as the steps involved in casting, demoulding and curing the ornament. In addition, guidance is given on how to colour the concrete and repair it if necessary.
Masonry
How to make concrete bricks and blocks
Provides the technical information required to set up and run a blockyard for small-scale manufacture of masonry units. Aspects dealt with include the feasibility study, selecting and establishing a site, selection of equipment, materials for blockmaking, trial mixes, production and quality control.
The manufacture of concrete paving blocks
This technical note covers basic principles and aims to assist manufacturers, particularly new manufacturers, to produce a durable and consistent product.
Mortars and Plasters
Common defects in plaster
Aimed at the homeowner who wishes to assess whether plaster is acceptable, and if not, what can be done about it. Defects usually fall into one of the following categories: Non-structural and structural cracks; debonding; lack of hardness; grinning; expansion and popping. Causes of the most commonly occurring defects are discussed and repair methods for each are suggested.
Concrete, plaster and mortar mixes for builders
Presented largely in graphic form, this practical leaflet gives the proportions for large and small batches of concrete, mortar and plaster. It includes brief guidelines on quantities of materials to order.
Mortar mixes for masonry
Mortar binds bricks and blocks together to give strength and stability to a wall. The leaflet discusses briefly the required materials and mix proportions to give freshly mixed mortars the necessary softness and plasticity. It also covers batching, mixing and handling the mortar as well as quantities of materials to order for mortar mixes per cubic metre or per 50 kg bag of cement.
Repairing the surface of concrete – casting defects and minor damage
Intended to assist those responsible for specifying, supervising or carrying out relatively superficial repairs to concrete. Types of defects and their causes are given as well as repairs of various types and the use of different materials. Repairs to effect structural changes and repairs of cracks fall outside the scope of this leaflet. Repair materials are limited to formulations based on portland cement.
Successful plastering
Sand-cement plaster is used extensively in building work as a decorative or protective coating to concrete and masonry walls and concrete ceilings. This publication gives the technical information needed for successful plastering and covers selection of materials, mix proportions, surface preparation and plaster application for conventional architectural purposes. Special applications such as squash courts and swimming pools are outside its scope.
Sports Facilities
Concrete cricket pitches
Concrete provides a permanent solution to the problem of ever-increasing maintenance costs associated with the traditional turf pitch, whether for matches or for practice. The leaflet discusses pitch layouts, site preparation, concrete mixes and quantities, reinforcement, joints, placing and compacting, and finishing and curing the concrete.
Plastering squash-court walls
The plaster on playing walls of squash courts has to be hard and strong and its surface must be a true plane with a fine matt texture. This leaflet gives information on construction requirements, the plastering system, materials, batching and mixing, quantities of materials and repair of localised failures.