Spanish experiences in roller compacted concrete pavements in the years 1984-85

Roller compacted concrete pavements have been used in e~ght experiences, with about 100,000 m2 paved in d1fferent parts of the country and diverse orographical and ~limatological conditions(Barcelona, Valencia, Valladol1d, Leon, Sevilla and Zaragoza). According to the same standard specifications, pavements have been built with different material properties, concrete mixing procedures and construction methods. In reference to material, siliceous or calcareous aggregates have been used, total or partial crushed. A mixture of Portland cement and fly-ash has been ~he cementitious material with dosages of cement vary- 1p~ between 65 and 50% and fly-ash varying between 3S and 50%. Cementitious material dosages have ranged between 300 and 360 kg/m3 • High-time or few-lime fly-ash have been used and added to concrete in concrete plants near of the site wor~ or in cement plants (pozzolanic cement). Concrete has been mixed in mixing plug mills or mixing trucks with dosages by weight volume of its components. To transport the concrete to the work site, dump trucks have been used over a distance less than 20 km in all the cases. The RCC has been placed with asphaltic concrete pavers or graders with good results in both cases. It has been compacted with a heavy wheel-pneumatic roller. Two curing procedures have been achieved: asphalt emulsions and special curing liquids. Quality control procedures have consisted of checking dens1ty and m01sture of concrete by nuclear density gages and sand method. Core samples have been taken and proper field samples made to test them for comp~ essive and splitting strength.