Advantages of Viscosity Grade Bitumen Viscosity grade bitumen is based on fundamental engineerin7g properties and not on empirical properties. It is a performance based grading system. Viscosity grading system takes into account both low and high temperature susceptibility of bitumen. Viscosity grade bitumen is very easy to handle as viscosity value at two different temperatures … Read more
Information to be Supplied by The Producer Before supplying any concrete, the producer should provide the following information to the purchaser. Nature and source of each constituent material Source of supply of cement Proposed proportions or quantity of each constituent/m3 of fresh concrete If any admixture is to be used to produce concrete, then following … Read more
Information to be Supplied by the Purchaser It is recommended that a meeting must be held between the purchaser and the producer of concrete. In the meeting the following points should be discussed. Details of concrete mix Use of concrete Type of structure Performance requirement Notice to be given prior to delivery Delivery rate Purchaser’s … Read more
Storing of Cement on Site – Guidelines Store cement in a building which is dry, leak proof and as moisture proof as possible. There should be minimum number of windows in the storage building. Stack the cement bags off the floor on wooden planks in such a way, so that it is about 150 mm … Read more
What is Mortar? It is a plastic mixture of binding material (like cement, lime, etc), fine aggregates (like sand, surkhi, etc), water and any admixture approved by the engineer in-charge. This is used to bond masonry or structural units. There are different types of mortar used in construction industry. The following are the type of … Read more
Atterberg Limits of Soil The term Atterberg limits is named as per the Swedish agriculturist Albert Atterberg. When water is added into a soil mass, it changes its state from solid to liquid. He divided the entire range from solid to liquid into four stages: The solid state The semi-solid state The plastic state The … Read more
What is Efflorescence on Plaster Surface? Efflorescence is one type of defect found on plaster surface. Efflorescence is the whitish crystalline substance which appears on the surface of walls due to presence of soluble salts, such as suphates of sodium, calcium and magnesium. Why Efflorescence Happens on Plaster Surface? Presence of salts in the lime, … Read more
Recommended Plaster Specifications A list of specifications for mixes suitable for various situations, which cover single-coat, two-coat and three-coat work is given in the table below. No. of Coat of Plaster Situation Mix proportion by volume (Cement:Lime:Sand) Single coat plaster Both internal and external 1:0:3 1:0:4 1:0:6 1:1:6 1:2:9 Two coat plaster Both internal and … Read more
Effect of Atmospheric Conditions on Plaster The prevailing weather at the time of plastering or during the setting, drying and hardening period may affect the finished work as follows: 1. Frost The destructive effect of frost on plaster work is significant. Unless special precautions are adopted, plastering work shall be suspended entirely during frosty weather. … Read more
Thickness of Plastering Finishing coats (and single-coat work, where employed) should be of such minimum thickness as just to provide a sufficient body of material to harden satisfactorily under the site conditions in any particular case. The total thickness of two-coat work exclusive of keys or dubbing out shall be generally about, but shall not … Read more