Essay On Road Construction

3163 Words7 Pages

INTRODUCTION
Transportation is the life line of any country and road sector is a major stakeholder contributing to the economic growth. According to National Highway Authority of India (NHAI), Indian road network consist of 33 lakh Km. and is the second largest in the world. Industrial waste by-products viz. Coal ash, Steel slag, Zinc slag, Jarofix etc. in road construction has gained widespread acceptance in India and abroad. This is due to widespread infrastructure development and depletion of natural resources viz. Soil and Aggregate and its impact on the environment. Though literature review indicates its utilization potential as an embankment fill material, its applicability in granular and bituminous layers needs in-depth research both at laboratory and field level. Considering the economic and environmental aspects, such industrial by-products can be investigated for its feasibility as a replacement of fine aggregate in sub-base and base layer of road pavement. In the wake of depletion of natural available resources, MORTH (Ministry of Road Transport and Highways), IRC (Indian roads Congress) have strongly recommended to search and use alternative and local materials for road construction. Such locally available material and alternative material can be stabilised with stabilizers like Cement, Lime etc and after detailed laboratory study, it can be used in base and sub-base layer of pavement section.
These cement stabilised material are characterized by its stiffness property and its tensile strength. AUSTROADS (2008), NCHRP (2004) recommends Mechanistic-Empirical (M-E) approach in which material is characterized by its resilient stiffness modulus and thickness design by cumulative damage analysis using fatigue life analysi...

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... cement stabilised recycle crushed concrete at frequency of 2 Hz, 5Hz,8Hz and 13.3 Hz and concluded that resilient stiffness modulus is independent of frequency in applied frequency range.

Fig.25 Set-up for Resilient Modulus testing of material

Table9. Table for Resilient Modulus (MPa) value for different cement content and curing period
Cement content (%) 3% 6% 9%
Curing Period(days) MEAN S.D %Cv MEAN S.D % Cv MEAN S.D %Cv
7 Day Curing …….
…….
……. ..…
……
…… ……
……
…… 3171
3208
3259 136.12
129.9
142.33 ……
…...
…… …...
…...
…...
14 Day Curing 1857
1791
1836 43.82
43.56
29 4089
3967
…… 88.66
62.99
…… 6276
6299
…… 80.58
89.60
……
21 Day Curing 1903
1944
1907 51.7
41.84
76.93 4987
4728
4688 96.61
121.43
103.51 7564
7349
7513 113
161.05
186.14
28 Day Curing 2304
2241
2242 180.8
130.71
85.72 6854
6970
….. 89.57
89.34
…… 8677
8571
8653 50.15
86.71
56.40

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