Laboratory Evaluation and Field Construction of Roller-Compacted Concrete for Testing under Accelerated Loading

Abstract

The Louisiana Department of Transportation and Development has seen a rapid decline of low-volume roadway serviceability in recent years as a result of oil and gas exploration within the Fayetteville Shale Play near Shreveport, Louisiana. Similar results are expected on the low-volume roadway network within the Tuscaloosa Shale Play, north of Baton Rouge, Louisiana, as exploration expands. The objectives of this research were to determine appropriate proportions of roller-compacted concrete mixture for the construction of accelerated loading test lanes and to document field construction activities. Concrete samples were produced with four cement contents to determine the effect of moisture and density; the samples were tested for compressive strength at 7 and 28 days of age. The field testing included nuclear density testing, thickness measurements, and field-prepared compressive strength specimens. A walking profiler was used to determine the international roughness index (IRI). All laboratory-produced mixtures exceeded a compressive strength of 4,000 pounds per square inch (psi). When the desired surface characteristics and density were considered, 450 lb/yd3 was chosen as the minimum cementitious content for the construction of the test lanes. The field construction results showed that the speed of construction affected the density, the IRI, and the surface characteristics. An increased speed of construction yielded a rougher surface texture (an increased IRI between 360 and 620 in./mi) and slightly lower densities. The compressive strengths were still adequate and exceeded 4,500 psi at 28 days old. On the basis of the field results, IRI values in the 100- to 130-in./mi range and compressive strengths exceeding 5,000 psi may be expected in a full-scale roadway construction effort.