PACKING DENSITY OF AGGREGATE
The packing density of aggregate gives an indication of how efficiently aggregate fill a certain volume and for that reason is such an important concept in concrete technology.
Aggregate Properties
HOW AGGREGATE PROPERTIES AFFECTS CONCRETE PROPERTIES?
INFLUENCE OF AGGREGATE PROPERTIES ON CONCRETE Aggregates influence the properties of concrete/mortar such as water requirement, cohesiveness and workability of the concrete in plastic stage, while they influence strength, density, durability, permeability, surface finish and colour in hardened stage. Aggregates are generally classified into two categories viz. natural and manufactured/processed. Geologically aggregates may be obtained … Read more
PROPERTIES OF AGGREGATES FOR CONCRETE
Properties of Aggregates Approximately 75% of the volume of concrete is occupied by aggregates, so quality of aggregates plays an important role in determining properties of concrete. Aggregates are chemically inert, solid bodies held together by the cement. Aggregates come in various shapes, sizes, and materials ranging from fine particles of sand to large, coarse … Read more
WHAT ARE THE PROPERTIES OF AGGREGATES FOR CONCRETE?
Engineering Properties of Aggregates Aggregates are used in concrete to provide economy in the cost of concrete. Aggregates act as filler only. These do not react with cement and water. But there are properties or characteristics of aggregate which influence the properties of resulting concrete mix. These are as follow. Composition Size & Shape Surface … Read more
HOW TO EVALUATE QUALITY OF AGGREGATES FOR ASPHALT CONCRETE?
Aggregates for Asphalt Concrete The amount of aggregates for asphalt concrete mixtures is generally 90 to 95 percent by weight and 75 to 85 percent by volume. Aggregates are primarily responsible for the load supporting capacity of a pavement. Aggregate has been defined as any inert mineral material used for mixing in graduated particles or … Read more
HOW TO BLEND AGGREGATE USING SURFACE INDEX VALUE?
Surface Index of Aggregates Surface index of aggregates is another way to represent the specific surface of aggregate. This method was suggested by Murdock. Murdock provided some empirical numbers to represent the specific surface of different aggregates grading (as shown in the table below). Surface Index Values for Single Graded Aggregate TABLE-1 Sieve Size Within … Read more
HOW TO DECIDE MAXIMUM SIZE OF COARSE AGGREGATE TO BE USED IN CONCRETE?
For the same strength or workability, concrete with large size aggregate will require lesser quantity of cement than concrete with a smaller size aggregate. In a mass concrete work the use of larger size aggregate will be useful due to the lesser consumption of cement. This will also reduce the heat of hydration and the … Read more
HOW TO INSPECT PHYSICAL CHARACTERISTICS OF AGGREGATE USED IN CONCRETE?
While inspecting aggregate for quality control purpose, it is required to describe its physical properties, because physical properties of aggregate have an effect on the property of concrete. The physical properties of aggregate which should be described are given below. Name of parent rock & Group name Particle Shape Surface Texture Let us see how … Read more
HOW TO BLEND AGGREGATE USING FINENESS MODULUS VALUE?
Sometime it may happen that, the aggregate available at site is not conforming to the desired grading. In such case two or more aggregates from different sources may be combined to get the required grading. Fineness modulus value can be used as a technical way to blend coarse aggregate with fine aggregate to produce desired … Read more
HOW TO TEST AGGREGATE FOR BULK DENSITY AND VOIDS?
Objective Determination of unit weight or bulk density and void of aggregates. Equipments Name Capacity 1. Balance Sensitive to 0.5% of weight of material 2. Cylindrical metal measure Of 3 litre capacity (for fine aggregate) Of 15 litre capacity (for aggregate upto 40mm) 3. Tamping rod 16 mm dia. and 60 cm long Sample Preparation … Read more