The Geotechnical laboratory deals with the measurement of the strength of the earth’s surface and foundation. This helps people to understand and create the crust of the surface that we walk and drive on every day. Soil consists of a multiphase aggregation of solid particles, water, and air. This fundamental composition gives rise to unique engineering properties, and the description of its mechanical behaviour requires some of the most classic principles of engineering mechanics. To an engineer, soil is a material that can be:
Prior to commencement of any road construction project involving site formation work, site investigation is carried out to establish the geological profile along the road alignment. Pavements are a conglomeration of materials. These materials, their associated properties, and their interactions determine the properties of the resultant pavement. Thus, a good understanding of these materials, how they are characterized, and how they perform is fundamental to understanding pavement. The materials which are used in the construction of highway are of intense interest to the highway engineer. This requires not only a thorough understanding of the soil and aggregate properties which affect pavement stability and durability, but also the binding materials which may be added to improve these pavement features.
TESTING OF SOIL
The characteristics of soil like fineness, deleterious materials, compactness & bearing strata are defined as per IS specification as well as Indian Road Congress. The vital tests for road construction are done in this Soil Section of the Assam Road Research & Training Institute which are mentioned below.
Sub grade soil is an integral part of the road pavement structure as it provides the support to the pavement from beneath. The sub grade soil and its properties are important in the design of pavement structure. The main function of the sub grade is to give adequate support to the pavement and for this the sub grade should possess sufficient stability under adverse climatic and loading conditions. Therefore, it is very essential to evaluate the sub grade by conducting the necessary tests as shown below-
| Area | 72 Sqm (approx.) |
| Laboratory Staff | Assistant Engineer-2, Field Assistant and Bearers |
| Contact | Director, Assam Road Research and Training Institute, PWRD, Fatashil Ambari, Guwahati-25 Assam |
| dir.arrti-as@nic.in,arrti.director@gmail.com |
Tests conducted at Soil Section with approved rates are as follows:
|
Sl. |
Name of |
Name of |
Rate per |
Equipments/Apparatus |
|
1. |
Soil |
Sieve Analysis |
500 |
IS Sieves of size 4.75mm, 2.36 mm, 1.18mm, 600 micron, 425 micron, 75 micron |
|
2. |
Limit Test |
600 |
Casagrande Apparatus(set), Flash water Bottle, Smooth and Rough Glass sheet, spatula etc |
|
|
3. |
Proctor Density(Standard) |
2500 |
Standard Proctor Mould, Proctor Hammer, Measuring Cylinder, Balance 10 kg capacity and 0.01 gm to 1 kg accuracy, Crucible, Thermostatic Oven etc. |
|
|
4. |
Proctor Density(Modified) |
4000 |
Modified Proctor Mould, Proctor Hammer, Measuring Cylinder, Balance10 kg capacity and 0.01 gm to 1 kg accuracy, Crucible, Thermostatic Oven etc. |
|
|
5 |
CBR Test |
3000 |
CBR machine(set),Mould, Rammer, Water Tank, Balance 10 kg, Weight, Perforated Plate, Blotting Papers 12.5mm size etc. |
|
|
6 |
Swelling Index Test |
365 |
425 µ Sieve , glass cylinders two 100 ml capacity |
|
|
7 |
Field Density by Sand Replacement Method |
5000 |
Cylindrical core cutter 100mm inner dia x130mm long, standard sand 1 bag |
|
|
8 |
Field Density by core cutter Method |
1000 |
Cylindrical core cutter , Rammer,Balance10kg capacity, Rapid moisture meter etc. |
|
|
9 |
CTB mix design |
15000 |
Cylindrical mould(6 nos), proctor mould sets, Compression Test Mechine(CTM), Balance etc. |