There are two types of Plastics, namely Thermoplastic and Thermosetting plastics distinguished by the physical property. Thermoplastics: This type can be softened by heating after they have been cured and remoulding cycle can in theory be repeated an indefinite number of times but in practice some defects may eventually take place. The curing process is(…)
Building Materials
PRE-CONCRETE CHECKS FOR FORMWORK & RELEASE AGENTS
PRE-CONCRETE CHECKS FOR FORMWORK: Before the concrete is poured into the formwork, it must be checked by someone who has been trained to inspect formwork. Depending on how big or complicated the pour is, the inspection may just take few minutes or it could take hours. Only when the formwork has been approved, may the(…)
FORMWORK AND GOOD FORMWORK PROPERTIES
What is formwork? When concrete is fresh and in its liquid state it must be restrained within a mould in order for it to set in its required shape. Formwork is the term used to describe this mould. For most in-situ pours, the formwork is made of wood. A smooth outer surface provides the main(…)
SUITABILITY OF VARIOUS TYPES OF CEMENT
Suitability of various types of cement: Selection of cement based on suitability for various concreting environment is important for durability considerations of structures. Thus, making wise choice of cement type for particular construction site, prevents structure from deteriorating and saves much repair and rehabilitation cost later. Following are the suitability of various cements for different(…)
ESTIMATION METHODS OF BUILDING WORKS
The estimation of building quantities like earth work, foundation concrete, brickwork in plinth and super structure etc., can be workout by any of following two methods: a) Long wall – short wall method b) Centre line method. c) Partly centre line and short wall method. a) Long wall-short wall method: In this method, the wall(…)
SPECIFICATION FOR MARBLE MOSAIC TILE FLOORING
The laying and finishing of cement concrete marble mosaic flooring tiles in floors, wall, staircases, etc. is discussed here. Materials required for mosaic tile flooring: Cement, sand, terrazzo tiles shall conform to the specifications detailed in the relevant standard code. Mixing of mortar is done as per the specification for grade of mortar to be(…)
SPECIFICATION OF A GOOD QUALITY BRICK
Following are the requirement of a good quality bricks: (a) Bricks for masonry in foundations, walls and other locations shall be hand or machine moulded and made from suitable soil and kiln burnt. They shall have regular and uniform size and colour, sharp straight and right angled edges and deep cherry red and copper colour,(…)
SETTING PROCESS OF CEMENT
When water is mixed with cement to form a paste, reaction starts. In its pure form, the finely ground cement is extremely sensitive to water. Out of the three main compounds, viz. C3A, C3S and C2S, reacts quickly with water to produce a jelly-like compound which starts solidifying . The action of changing from a(…)