REINFORCED FLY ASH SUB-BASES IN RURAL ROADS

PRESENTED BY:

SOURABH JAIN

Fly ash is a waste by-product from thermal power plants, which use coal as fuel.

At present about 100 thermal power plants in India produce about 130 million tonnes of fly ash every year.

The construction of roads using fly ash helps to consume bulk quantities of fly ash solving its disposal problems to certain extent but also satisfies the construction requirements.

INTRODUCTION

To observe the effect of reinforcement on conventional parameters (engineering properties) of fly ash.

To study the effect of reinforcement on rut depth formation on model section with simulation of field conditions.

OBJECTIVES OF THE STUDY

Fly Ash From N.T.P.C. Ghaziabad (UP).

As per Bureau of Indian Standard (BIS) it is also classified as silt of low compressibility. (ML) Soil Roorkee soil is used in present study.The soil used can be

classified as poor graded fine sand (SP). Reinforcement.

Fiber used in the present investigation is polypropylene fiber manufactured from high-density polypropylene and polyethylene.

MATERIAL CHARACTERISATION

PROPERTIES OF FIBER

Proctor Compaction Test Results

California Bearing Ratio Test results

Plate Load Test Results

Dynamic load test in model test tank

Analysis of fiber reinforced fly ash

Modified compaction tests.

PROCTOR COMPACTION TEST RESULTS

Analysis of test results showed that both optimum moisture content and maximum dry density for all the types of soils, decreased with an increase in fiber content.

CALIFORNIA BEARING RATIO TEST RESULTS

California Bearing Ratio (CBR) of fly ash increased with increase in percentage of fiber content at a particular aspect ratio.

PLATE LOAD TEST RESULTS

modulus of subgrade reaction (k) increases by introducing the fiber with fly ash.

The k-value at 0.2 % fiber content increases 15.47 %, 21.4 % and 51.2% for fly ash, fly ash + 15 % soil and fly ash +25 % soil respectively.

Steel tank (60x60x60cm) for repeated loading tests.

Four layers of pavement: Subgrade layer (200 mm) Sub base layer (210 mm) Base layer of WMM (150mm) Surface layer (25mm)

DYNAMIC LOAD TEST IN MODEL TEST TANK

10 cm plate used to transfer load from plunger to the pavement surface.

The numbers of load cycles applied on the model are limited to 10,000 only.

Volume of traffic is considered medium. (4100 kg wheel load)

This whole stimulation is used to calculate rut depth of pavement.

Rut depth is indicator of life of a pavement.

Fly ash alone have 6.07 mm rut depth. But in case of fly ash with 25% soil and 0.2% fiber rut depth is nearly half of the rut depth in case of fly ash.

Both optimum moisture content and maximum dry density for all the types of soils, decreased with an increase in fiber content.

California Bearing Ratio (CBR) of fly ash increased with increase in percentage of fiber content at a particular aspect ratio.

Modulus of subgrade reaction increases with increase in fiber content at constant fly ash content.

The rut depth of pavement decreases with increase in fiber content hence life of pavement increases.

CONCLUSIONS

“Reinforced flyash in rural road sub-bases.”published in indian road congress (IRC) journal.

Rural Roads Manual (IRC-SP:20-2002), Indian Roads Congress, New Delhi.

Textbook “soil mechanics and foundation engineering” by B.C. Punmia.

Textbook “Highway materials and pavement testing” by Khanna and Justo

REFERENCES