Building Materials
...ing industry, however the production process of the ceramic material must comply with the correct procedure otherwise the product will not meet strength requirements. Answer to Question 2 a) The term workability can be defined as a range of ability to manipulate the physical form or structure of concrete or any material in question. b) Workability: Influencing Factors. 1. Water Content – Noted as the most important factor to the workability of concrete. When the water level in concrete gets too high, the concrete resembles a paste making the concrete increasingly workable. 2. Aggregate Type and Grading – Workability of concrete is said to be directly proportional to the size of the aggregate involved. The grading of aggregate reverses the effect of water content. 3. Type and Quantity of Concrete – For workability ease the fineness of concrete sediments will lower as the surface area increases. 4. Temperature & Time – To maintain workability in concrete the user must monitor the temperature, if it becomes less desirable to concrete will lose it manoeuvrability. Workability is also affected as the setting time increases. c) Methods of Measurement. 1. Slump Test – measures the degree of wetness and consistency of concrete. 2. Compacting Factor – measures the mass of compacted concrete. 3. VeBe Test – This test predicts the response to compaction. It uses vibration to erase air particles for the matter. This is relevant to building slabs as the concrete is poured and mechanically vibrated to reduce air pockets, which cause strength failure. Answer to Question 3 Concrete hollow blocks are used in all types of constructions throughout the building industry, due to the various advantages they have opposed to solid blocks and clay bricks. There are many reasons blocks have been formed as hollow structures, these findings are backed by structural engineers across the globe. • Lighter – enabling a large building to be constructed lighter, reducing foundation stress. • Hollow block are able to be reinforced by core fill, which can be braced with steel horizontally and vertically. • Hollow blocks absorb less water. • Hollow blocks are fire resistant. • Hollow blocks have heat and sound insulating characteristics. • Hollow blocks are environmentally friendly. • High rise buildings up to 35 stories can be constructed by load bearing block walls. • Concrete block are able to be directly painted, reducing construction time. Pressed concrete blocks is the modern preferred method of manufacturing as structural consistency is greatly achieved producing a reliable building component for construction use. The compaction from the pressing procedure greatly strengthens the block as all possible air pockets are extracted from to component. The method of manufacturing pressed concrete blocks greatly reduces harmful environmental hazards in comparison to the kiln method which disperses large amounts of dust, smoke and ash into the atmosphere. 3b) A block with a code number 15-32 would consist of the following factors. • Solid Construction • 200mm block height • 150mm block width • 300mm block length. This code number is not commonly manufactured but is possible for special orders from most manufactures of concrete block. Answer to...