What is Curing? Curing is a procedure of promoting the hydration of cement for development of concrete strength and controlling the temperature. As a result of curing, we can achieve higher strength and reduced permeability which is very vital for long term strength or durability. The effect of curing has been shown in the following … Read more
What is Compaction? Compaction is a process of expelling the entrapped air. If we don’t expel this air, it will result into honeycombing and reduced strength. It has been found from the experimental studies that 1% air in the concrete approximately reduces the strength by 6%. Different Methods Of Concrete Compaction There are two methods … Read more
1. Backhoe Backhoe comprises a bucket on the end of an articulated boom, set on a pneumatic tyred or crawler tractor unit. The boom, bucket arm and bucket are usually controlled by hydraulic rams. Back-acters operate by digging towards the machine in an arc from a small distance above the surface on which the machine … Read more
Aim To determine porosity and density of rock using saturation and buoyancy techniques as per IS-13030-1991. Apparatus Oven (capacity 105±30C) Balance (Accuracy of 0.01% of the sample weight) Non corrodible sample container Vacuum vessel for immersion of sample (capacity 0.8 kPa) Immersion bath, wire basket for determination of saturated-submerged weight) Procedure Take at least 10 … Read more
Objective Determination of CBR of soil either in undisturbed or Remoulded condition Reference Standards IS: 2720(Part 16)-1973- Methods of test for soils: Laboratory determination of CBR. Equipments / Apparatus Compression machine Proving ring, Dial gauge, Timer Sampling tube Split mould Vernier caliper, Balance Preparation sample The test may be performed (a) On undisturbed soil specimen … Read more
Methods of Concrete Transportation Transportation of concrete is an important activity in the production of concrete. The time taken in transit should be a design parameter as it depends on the initial setting time as well as the requirement of workability at the destination. The method of transportation adopted at site should be decided in … Read more
What is Admixture? It is an optional ingredient of concrete which is added to modify the properties of fresh and hard concrete and grout materials as per some specific requirements. Addition of admixture may alter workability, pumping qualities, strength development, appearance etc in fresh concrete and permeability, strength, durability etc in hardened concrete. But use … Read more
The followings are general recommendations or considerations for hot weather concreting. Guidelines to Follow 1. Do not exceed the maximum allowable water-cementious materials ratio or the manufacturer’s maximum recommended dosage of any admixture. 2. Consider retarding admixtures if their performance has been verified during trial batches. 3. Substitute ground, granulated blast furnace slag for part … Read more