Before knowing the term workability let us look at some of the definitions given by scientists and researchers. Definitions of Workability of Concrete According to Granville “it is that property of the concrete which determines the amount of useful internal work necessary to produce full compaction.” Powers defined it as “that property of plastic concrete … Read more
Mix design is a process of selecting suitable ingredients and determining their relative proportions with the objective of producing concrete of having certain minimum workability, strength and durability as economically as possible. Concrete A mix design can be designed in two ways as explained below Nominal Mix Design Nominal Mix It is used for relatively … Read more
Aim To determine the field density of soil at a given location by sand replacement method Reference IS-2720-Part-28-Determination of dry density of soils in place, by the sand replacement method Apparatus Sand pouring cylinder Calibrating can Metal tray with a central hole Dry sand (passing through 600 micron sieve) Balance Moisture content bins Glass plate … Read more
What is Gap Graded Aggregate? Generally we use well graded aggregate or continuous graded aggregate, which means representation of all the standard particle sizes in certain proportion. Assumption made in well gradation is that voids created by the higher size of aggregate will be filled-up by immediate next lower size of aggregate and again some … Read more
Aim To determine the field density of soil by core cutter method Reference IS-2720-Part-29-Determination of dry density of soil in place by the core-cutter method Apparatus Cylindrical core cutter Steel rammer Steel dolly Balance Steel rule Spade or pickaxe Straight edge Knife Procedure Measure the height (h) and internal diameter (d) of the core cutter … Read more
Field Tests on Cement There are some field tests which gives some basic idea about the quality of the cement without elaborate facility of laboratory in the field. These tests are as given under Date of manufacture should be seen on the bag. It is important because the strength reduces with age. Open the bag … Read more
The principle terms used by civil engineers to describe soils are Gravel (particle size larger than 4.75 mm) Sand (particle size within 4.75 mm to 0.075mm) Silt & Clay (particle size less than 0.075mm) Most natural soils consist of a mixture of two or more of these constituents and may contain an admixture of organic … Read more
The embankments are constructed with locally available soils, provided it fulfils the specified requirements. Procedure of compaction to be adopted will depend on the type of soil being used in construction. General guidelines to deal with compaction of various types of soils for attaining optimum dry density/relative density at minimum effort, have been briefly given … Read more
When a Portland Slag cement is tested for its physical requirements, then it must satisfy the following specifications given by IS 12269. The fineness value of PSC when tested by Blaine’s air permeability method shall not be less than 225 m2/kg. The expansion value (i.e. soundness) of unaerated cement when tested by Le-Chaelier method shall … Read more
When a calcined clay based Portland Pozzolana cement is tested for its physical requirements, then it must satisfy the following specifications given by IS 1489-Part 2. The fineness value of fly ash based PPC when tested by Blaine’s air permeability method shall not be less than 300 m2/kg. The expansion value (i.e. soundness) of unaerated … Read more