From durability point of view, the grade of masonry mortar to be used for a given work is primarily dependent upon the following two factors. Loading condition Exposure condition Considering the above two factors the suitable grade of masonry mortar to be used for different works is given in the following table. Generally cement mortar … Read more
Grading Limit of All in Aggregate Sieve Size Percentage of Passing For All-in-Aggregate 40 mm Nominal Size 20 mm Nominal Size 80 mm 100 – 40 mm 95 – 100 100 20 mm 45 – 75 95 – 100 4.75 mm 25 – 45 30 – 50 600 micron 8 – 30 10 – … Read more
The sand which is used in mortar can be natural sand, or crushed stone sand or crushed gravel sand. Sand or fine aggregate which is used in concrete is somewhat different from sand which is used for masonry mortar. The role of sand in mortar is to give the following properties such as Strength Workability … Read more
What is Fineness Modulus of Aggregate? Fineness modulus is an empirical factor obtained by adding the cumulative percentages of aggregate retained on each of the standard sieves ranging from 80 mm to 150 micron and dividing this sum by 100. Why to Determine Fineness Modulus? Fineness modulus is generally used to get an idea of … Read more
Reference IS: 650 – Standard sand for testing cement – specification Standard Sand Standard sand is used to assess the quality of cement, lime, pozzolana and other mineral admixture used in construction industry. Previously it was imported from U.K. Now it is available at Ennore, Madras. Characteristics Standard sand shall be of quartz material Colour … Read more
Specification For Mechanical Properties of High Strength Deformed Bars & Wires Reference IS-1786-2008-High strength deformed steel bars & wires for concrete reinforcement Type 0.2% proof stress/ yield stress, Min, N/mm2 0.2% proof stress/ yield stress, Max, N/mm2 TS/YS ratio Elongation, %, Min, on gauge length 5.65√A, where A is the cross-sectional area of the test … Read more
Our aim is to mix the fine aggregate & coarse aggregate in such a ratio so that the final combined aggregate gives the specified or desirable surface index. Follow the below mentioned steps to find the proportion of fine to coarse aggregate. Procedure Calculate the total surface index of fine aggregate (let it be x) … Read more
Aggregate impact value test gives an indication of aggregate’s toughness property (i.e. property of a material to resist impact) Aggregate impact values are used to classify the stone aggregates with respect to toughness property as given below. Aggregate impact value (%) Toughness Properties <10 Exceptionally tough / Strong 10 – 20 Very tough / Strong … Read more
The grading of coarse aggregate may be varied through wider limits than that of fine aggregates, since it does not affect the workability, uniformity and finishing qualities of concrete mix. As per IS-383 the grading limit of coarse aggregate, both for single size as well as graded should be as per the table given below. … Read more
Aggregate should have the following qualities Quality Requirements of Aggregate Aggregates should be strong, hard, dense, durable, clear and free from veins and adherent coating. Aggregates should be free from injurious amounts of disintegrated pieces, alkalis, vegetable matter and other deleterious substances. Flaky and Elongated pieces should not be present in aggregate mass. Aggregate crushing … Read more