Concrete has been categorized as a key contributor of CO2 (carbon) emissions into the atmosphere. This is mostly associated with the production of ordinary portland cement (OPC). The concrete and cement industries are pursuing a path to reduce their carbon emissions generally in accordance with the climate change goals outlined...
Construction is a strategically important industry and its productivity has a significant impact on a nation’s economy. However, productivity in the US construction industry has been widely reported to be on the decline. Among several causes identified, the lack of innovation in project management practices has been described as having...
The issue of chloride-induced corrosion of reinforcing steel in concrete and its economic impacts are well-known. Chlorides that cause reinforcement corrosion can be from constituent materials used to prepare concrete or can enter the hardened concrete when the structure is exposed to chloride environments. To minimize the risk of reinforcement...
The constituent materials of concrete often contain chlorides. The presence of chlorides in sufficient amounts can disrupt the passive layer, also known as the passive film, that protects the reinforcing steel in concrete. This disruption can lead to premature corrosion of the reinforcing steel in concrete. To minimize the risk...
The use of high strength steel reinforcement has the potential to provide economic and constructability benefits when used in reinforced concrete structures. However, more research is needed to justify and confidently allow its use. Current design provisions limit the nominal yield strength of reinforcing steel bars to 60 ksi (420...
Significant progress has been made over the past 20 years in developing models to estimate the service-life of reinforced concrete systems. The basic understandings of the mechanisms that control the transport of ions and moisture in concrete systems have been well researched and models for determining corrosion initiation, specifically chloride-induced...
Use of high-strength steel (HSS) reinforcing bars could provide constructability and economic benefits for the construction of structures, reducing the initial and ultimately the life-cycle cost of bridge and building structural elements. This thesis summarizes work performed in a research project on the use of HSS reinforcing bars for concrete...
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...
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...
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...