Suryakanta The aggregates should be stored near the mixer A clean dry and hard surface should be selected for the storage. Aggregates should not be dumped on loam or grass. In the absence of clean and hard surface a platform constructed of wooden planks, old iron sheets, bricks or lean cement concrete may be used. During … Read more
Methods Used For Curing of Concrete There are various methods of curing. The adoption of a particular method will depend upon the nature of work and the climatic conditions. The following methods of curing of concrete are generally adopted. Shading concrete work Covering concrete surfaces with hessian or gunny bags Sprinkling of water Ponding method … Read more
When concrete is compacted with vibrators the following precautions may be taken to produce a concrete of good quality. The formwork should be strong and tight so that there is no leakage of mortar. The leakage of mortar results in honey combing. A lining of plywood may be provided to prevent the leakage if the … Read more
What is Standard Deviation? When repeated measurements give different results, we want to know how widely spread the readings are. The spread of values tells us something about the uncertainty of a measurement. By knowing how large this spread is, we can begin to judge the quality of the measurement or set of measurements. The … Read more
Output of a Concrete Mixer The output of a mixer essentially depends upon the capacity of a mixer. In addition, it depends upon the duration of mixing, supply of materials to the mixer and the speed at which charging and discharging operations are carried out. Sometimes the speed of transporting concrete from mixer to the … Read more
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