Using recycled concrete aggregate (RCA) as a replacement for natural aggregate in new concrete is a promising way to increase the overall sustainability of new concrete. This has been hindered, however, by a general perception that RCA is a sub-standard material due to the lack of technical guidance, specifically related...
Most specifications for ready-mix concrete (RMC) limit mixing time to 90 minutes and/or truck drum revolution counts (DRC) to 300 before discharge. These specifications have been in place for many years with the objective of ensuring the quality and performance of the finished concrete product. However, limited research has been...
Alkali silica reaction (ASR) and corrosion of reinforcement are two deterioration mechanisms in reinforced concrete (RC) structures. These deterioration mechanisms can significantly damage a RC structure and reduce its service life. Supplementary cementitious materials (SCMs) are commonly used to improve the durability of RC systems containing reactive aggregate that are...
Driver distraction is a commonly observable phenomenon with a significant effect on the transportation network. Although the negative effects of driver distraction on safety are commonly studied, there has been little effort made to investigate the impacts of distraction on efficiency.
This study will examine driver behavior in standing queues...
Cast-in-drilled-hole (CIDH) piles are often constructed to depths that are inaccessible to internal vibration of the concrete. Internal vibration is necessary to consolidate the concrete and, if not performed, then typically inspection pipes are necessary to detect the presence of voids in CIDH piles. Void detection is critical to assessing...
At signalized intersections, pedestrians are considered to be amongst the most vulnerable. When in the crosswalk at intersections without protected left-turn phasing, pedestrians are particularly at risk from left-turning vehicles. Until recently, a wide variety of indications were in use across the US to indicate a permissive left-turn condition to...
Pedestrian distraction at roadway crossings has been correlated with a higher risk of pedestrian-vehicle collisions due to the pedestrian's cognitive, visual, and motor attention being drawn to a wide variety of secondary tasks.
This study is different from previous field studies of pedestrian midblock crossings in that the geometric layout...
Corrosion of reinforcement is recognized as the predominant factor that limits the service life of reinforced concrete (RC) structures exposed to aggressive environments. This corrosion deterioration can lead to damage resulting in capacity loss or even failure. For structures exposed to coastal marine environments or deicing or anti-icing applications, this...
Concrete is the most widely used construction material in the world. When constructing large concrete structures, concrete may have to be placed in multiple lifts. In these cases, fresh concrete is placed on hardened concrete. The interface that is formed between these two lifts of concrete is known as a...