Page 20 - bitbook

Performance Evaluation Report on Rural Roads Constructed Using CRRI-Bitchem Cold Mix in Different District of Assam during 2008-2009 13

5.0 Premix Carpeting using CRRI-BitChem Cold Mix Technology

The open graded premix carpet consist of small-sized aggregate premixed with a CRRI-BitChmen Cold Mix
binder. The open graded premix carpet construction involves use of premixed bituminous material laid in
compacted thickness of 20mm followed by a seal coat. IRC: 14(2004) describes the details for open graded premix
carpeting using CRRI-BitChem Cold Mix binder. The open graded premix carpet has been incorporated in
IRC:SP:20-2002 (Rural Roads Manual : Clause No.8.7.5.2).

5.1 Aggregates

The locally available aggregates were used for construction of pre-mix carpeting and seal coat surfacing on rural
roads. The quantities of aggregate required for Pre-mix carpeting and seal coat as per their nominal sizes are given
in the Table 1& 2.

Table 2. Quantity of Aggregates for Premix Carpeting

Aggregate Size Quantity per 10 sqm. of Road
Surface
Coarse Aggregate – Nominal Size 13.2 mm 0.18 cu.m.
Coarse Aggregate – Nominal Size 11.2 mm 0.09 cu.m.
Total quantity of aggregate 0.27 cu.m

Table 3. Quantity of Aggregates for Seal Coat
Seal Coat Type / Aggregate Size Quantity per 10 sqm. of Road
Surface
For Type A Seal Coat – Aggregate Size -6.7 mm 0.09 cu.m.
For Type B Seal Coat – Fine Aggregates-Medium 0.06 cu.m.

5.2 Binder

The quantity of binder required for Tack Coat, Premix Carpeting and Seal Coat is given in the Table 3.

Table 4. Quantity of Binder (BitChem Bitumen Emulsion) for Tack Coat

Item Quantity per 10 sqm. of Road
Surface
On a granular Surface (Already Primed) 2.5 to 3.5 kg.
On an existing black top surface 2.0 to 3.0 kg.

QSP/MR/19/ ACED/BTCM/214/2013 CSIR-NEIST/CNP-462