Uncategorized | Rollcon

Port of Savannah Chooses Roller-Compacted Concrete for Its Ocean Terminal Expansion

rcdev — Mon, 16 Nov 2020 17:52:48 +0000

In the fourth quarter of 2012, the Georgia Port Authority (GPA) held a bid to expand the capabilities of its Ocean Terminal, located off the banks of the Savannah River in Savannah, Georgia, to provide more storage for the loading and offloading of medium duty cargo at their primary terminal.

Moffat and Nichols, the Port’s engineering firm, approved bidders the option of using roller-compacted concrete (RCC) for the paving material. GPA had been using a hot mix asphalt (HMA) design, consisting of five inches of HMA over a 10-inch base of granular compacted material, for all of its pavements. The engineering caveat was that RCC had to be structurally equivalent to their typical 5/10 HMA design without adding additional cost.

Portland Cement Association

Performance of Thin Roller Compacted Concrete Pavement Under Accelerated Loading

rcdev — Mon, 16 Nov 2020 17:50:27 +0000

RCC is broadly defined as a stiff, low water concrete that is mixed and placed at a no-slump consistency, then compacted with vibratory rollers. RCC has similar strength properties and consists of the same basic ingredients as conventional concrete—well-graded aggregates, cementitious materials, and water—but has different mixture proportions. The major difference between RCC mixtures and conventional concrete mixtures is that RCC has a higher percentage of fine aggregates, which allows for tight packing and consolidation. RCC is a durable, economical, low-maintenance material for many pavement applications. It has been used for pavements carrying heavy loads in low speed areas because of its relatively coarse surface. However, in recent years its use in commercial areas and for local streets and highways has been increasing.

RCC Pavement Lays Foundation for Port of Houston Authority Projects

rcdev — Mon, 16 Nov 2020 17:48:41 +0000

Cost-effective and durable, roller-compacted concrete (RCC) pavement is laying a solid foundation for a number of significant projects for the Port of Houston Authority (PHA). By 2020, the Port is expected to have 380 acres of mostly 18-inch-thick RCC, making it the largest RCC site in the U.S. For perspective, a similar amount of RCC would fill a 6-inch-thick single lane road stretching more than 800 miles across Texas from Orange to El Paso.

Texas Contractor

Central Freight Yard Long Term Study

rcdev — Mon, 16 Nov 2020 17:45:13 +0000

Texas Contractor

Frost Durability of Roller-Compacted Concrete Pavements

rcdev — Mon, 16 Nov 2020 17:41:37 +0000

The growth of roller-compacted concrete pavement use in cold climate regions often is impeded by concerns regarding its ability to resist frost attack. Most published laboratory test results have indicated that the frost resistance and particularly the deicer salt-scale resistance of RCC are not always satisfactory. However, long-term field performance indicates that non-air entrainment RCC can be quite resistant to frost action. The report provides a comprehensive review on the current practices and recent developments in material selection and aggregate gradation, mixture design methods, production process and placement techniques. Improved construction techniques and recent developments in mixture design methods have resulted in stronger more durable RCC. Data shows that as little as 1.5% of spherical air bubbles can have a beneficial influence on the frost resistance durability of RCC. Test results indicate that ASTM C 1262 appears to be a reliable method of assessing the frost durability of RCC.

Service d’Expertise en Matériaux Inc.

Roller Compacted Concrete Over Soil Cement Under Accelerated Loading

rcdev — Mon, 16 Nov 2020 17:37:02 +0000

Thin Roller Compacted Concrete (RCC) pavement (i.e., the RCC thickness < 8 in.) has drawn a great deal of attention in recent years due to its potential application for low volume roadways where heavy and/or overloaded truck trafficking are often encountered. However, neither a structural design procedure nor load-induced pavement fatigue damage analysis is currently available for a thin RCC-surfaced pavement thickness design. The objectives of the study were to determine the structural performance and load carrying capacity of thin RCC surfaced pavements under accelerated pavement testing (APT), and to determine the applicability of using a thin RCC pavement structure with cement treated or stabilized base as a design alternative for those low volume roadways having frequently heavy truck trafficking.

In this study, six full-scale APT pavement sections, each 71.7 ft. long and 13 ft. wide, were constructed at the LTRC’s Pavement Research Facility (PRF) using normal pavement construction procedures. The test sections include three RCC thicknesses (4 in., 6 in., and 8 in.) and two base designs: a 150 psi unconfined compressive strength (UCS) cement treated soil base with a thickness of 12 in. and a 300 psi UCS soil cement base with a thickness of 8.5 in. over a 10 in. cement treated subgrade. A heavy vehicle load simulation device – ATLaS30 was used for APT loading. In-situ pavement testing, instrumentation, and crack mapping were employed to monitor the load-induced pavement responses and pavement cracking performance.

The APT results generally indicated that a thin RCC pavement (thickness of 4 to 6 in.) would eventually exhibit structural fatigue cracking failure under the repetitive traffic and environmental loading due to a combined effect of pavement cracking and pumping. The visible cracks first showed up on pavement surface as a single or several fine cracks along the longitudinal traffic direction within the wheel paths. The longitudinal cracks were then extended and gradually propagated to transverse and other directions under the continued loading, and finally merged into a fatigue cracking failure. Post-mortem trenching results showed that the majority of the cracks were bottom-up, but some did show developed as the top-down.

The results further showed that all tested thin RCC pavement structures over an adequate base support would have superior load carrying capability. The 6-in. RCC sections carried an estimated 87.4 million and 19.4 million ESALs to failure for the soil cement and cement treated base, respectively. The 4-in. RCC section over the soil cement base performed well with an estimated 19.2 million ESALs to failure. The data also indicated that the more substantial base (i.e., soil cement) support generally provided additional structural capacity as compared the less substantial cement treated soil base. The APT results were then used to evaluate the pavement fatigue life, cracking pattern and failure mode of thin RCC-surfaced pavements, which led to the development of a set of RCC fatigue models for thin RCC fatigue damage analysis. Finally, a thickness design procedure that includes a fatigue model suitable for analyzing a thin RCC-surfaced pavement structure was proposed and the corresponding construction cost savings when implementing thin RCC-surfaced pavement as a design option for a low-volume pavement were estimated.

Louisiana Transportation Research Center