Introduction to Sustainability of Structural Lightweight Concrete
Presented By: Jeffrey Speck
Affiliation:
Description: When considering the sustainability of structural lightweight concrete, there is a tendency to look only at the production of manufactured lightweight aggregates and its associated GWP, without considering the positive GWP impacts that derive from the the reduced dead loads and other aspects of lightweight concrete. This introduction to the topic includes a brief review of lightweight aggregate production, the effects of dead load reduction and case studies of projects that have reduced the carbon footprint of structures by taking advantage of lightweight concrete's design impacts.
Lifecycle Environmental Assessment of Internally-Cured Concrete for Bridge Deck
Presented By: Fariborz Tehrani
Affiliation: Expanded Shale, Clay and Slate Institute
Description: This presentation addresses the procedure for developing lifecycle analyses of bridge decks using internally-cured concrete. Internally-cured concrete materials containing fine expanded shale, clay, and slate (ESCS) aggregate extend the service life of concrete applications. Mitigation of early-age cracking and enhanced transport properties are vital characteristics of internally-cured concrete. These characteristics are vital for bridge decks and similar exposed applications to environmentally degrading conditions. The objective approach of this presentation involves environmental footprints associated with the production, transportation, use, decommissioning, and recycling of bridge deck materials and means and methods of construction, maintenance, retrofit, and replacement operations. Hence, lifecycle results achieve cradle-to-grave stages and beyond to develop environmental product declarations.
Fort Pulaski National Monument Entrance Bridge
Presented By: Kenneth Harmon
Affiliation: STALITE Lightweight Aggregate
Description: This project, near Savannah, Georgia, replaced a 2 lane, 1285-foot multi-span bridge with timber pilings and pile caps and a concrete deck. The bridge provides the only access to Ft. Pulaski National Monument and a US Coast Guard Station facility. The original bridge was replaced with a 1295-foot, 2 lane, multi-span concrete bridge that was a combination of precast-prestressed concrete piles and pile caps and an internally cured cast-in-place deck.
Benefits of Internal Curing for Concrete Pavement Overlays
Presented By: Peter Taylor
Affiliation: National Concrete Pavement Technology Center
Description: This presentation will discuss two test overlays constructed in Iowa containing lightweight fine aggregate for internal curing. We will review mixture proportioning, constructability, and test data as well as comparative smoothness data for the test sections and their controls. The data indicate that the internal curing not only increases projected life span based on mechanical properties but has improved smoothness at the time of placement and over time.
Role of Internal Curing on the Production of Sustainable Concrete
Presented By: Mehdi Khanzadeh-Moradllo
Affiliation: Temple University
Description: Internal curing (IC) using lightweight aggregates (LWA) is being introduced to improve the microstructure of concrete materials. However clear information is not available as to how IC may impact curing requirements and construction processes. This presentation will discuss the impact of IC using LWA on the durability and sustainability of concrete and construction processes and costs. Additionally, the important role of IC in the production of sustainable concrete mixtures using low-clinker binders will be highlighted. Low-clinker cementitious materials offer enormous CO2 reduction potential due to their significantly lower embodied energy, lowered calcination temperatures, and low clinker content. Based on experimental results, IC can be implemented to improve the fresh properties and microstructure of low-clinker materials (with high water demand) by extending the hydration/pozzolanic reactions.
Enhancing Performance with Internally Cured Concrete (EPIC2)
Presented By: Tim Barrett
Affiliation: FHWA
Description: Shrinkage cracking in concrete is a key limiting factor in achieving acceptable long-term performance in concrete bridges, roads, and repairs. This cracking may reduce the service life of transportation infrastructure leaving it in suboptimal condition to perform its intended function when exposed to continuous use, significant events, and a changing environment. Internal curing was developed to target and mitigate the source of shrinkage cracking by directly designing and integrally providing curing water to the concrete mixture. It is a practice ready technology that has been shown to mitigate shrinkage cracking, allowing for construction with higher performance concretes with estimated service lives that can exceed 100 years. The technology has been in various stages of deployment during the last two decades but remains an underutilized tool available to designers, specifiers, and owners. To address this, the Federal Highway Administration included internal curing in its Every Day Counts 7 initiative, Enhancing Performance with Internally Cured Concrete (EPIC2). This presentation will provide an overview of the initiative and summarize the resources it has made available to accelerate the implementation of internal curing.