... institute The products are made by soaking the base in bitumen, or thermoplas ticityelastomer(such as styrene butadiene-SBS),or ... thermoplastics(such as atactic polypropylene-APP,APAO,APAL)modified bitumen,the covering double faces with elastomer(SBS) or thermoplastics( ... APP,APAO,APAL)mldified bitumen, and last finishing the upward face with fine sands, ...