ACI Global Home Middle East Region Portal Western Europe Region Portal
Email Address is required Invalid Email Address
In today’s market, it is imperative to be knowledgeable and have an edge over the competition. ACI members have it…they are engaged, informed, and stay up to date by taking advantage of benefits that ACI membership provides them.
Read more about membership
Learn More
Become an ACI Member
Topics In Concrete
Home > Publications > International Concrete Abstracts Portal
Showing 1-5 of 309 Abstracts search results
Document:
SP364_7
Date:
December 1, 2024
Author(s):
Christopher J. Motter
Publication:
Symposium Papers
Volume:
364
Abstract:
Retrofit of reinforced concrete bridge columns with steel jackets is a commonly implemented strategy to increase column ductility in earthquakes. If the steel jacket retrofit is designed using available guidelines, fatigue fracture of longitudinal reinforcement is a likely cause of strength degradation. Fatigue fracture in reinforcement is dependent upon strain history in reinforcement. A model was developed to determine the strain history in longitudinal reinforcement at the plastic hinge in steel jacket retrofitted reinforced concrete columns. The model was validated with existing test data, and single degree of freedom nonlinear time history analyses were conducted using the model. Earthquake duration was shown to have a significant impact on the number of plastic excursions and the total plastic strain in the reinforcement, based on the results of analyses using an existing suite of long-duration earthquake ground motions that were each paired with a short-duration ground motion with similar response spectra. Results from analyses of 600 Magnitude-9.0 Cascadia Subduction Zone simulated site-specific ground motions for western Washington State were used in the formulation of a new testing protocol for steel jacket retrofitted reinforced concrete bridge columns that better accounts for expected demands in this region.
DOI:
10.14359/51745459
SP-362_07
June 5, 2024
Robert Lewis
362
The current mantra for our industry is “low carbon concrete,” but the question is – what do you actually mean by that? What is the benchmark you are using to say what is ‘low’– and how does that actually compare with what is being produced today? We’ve been making low-carbon concretes for decades – what we haven’t been doing is counting that carbon. Looking back at some history and at some recent projects, we can see that Low Carbon Concrete is certainly not rocket science and does in fact give us the durability and performance that we need for sustainability. The other side of the coin that we must be very wary of, in light of failures from the past, is that we produce concrete that is fit for purpose – making something that is ultra-green in the lab, but ultimately unusable in the real world serves no purpose and may even endanger lives. This paper shows a very small snapshot of the millions of cubic meters of binary, ternary, and quaternary cementitious blend concretes that have been used over the last 50 years, concentrating on more current examples showing that low carbon concrete is nothing new – it is already in major use.
10.14359/51740877
CI4507Goodwin
July 1, 2023
Fred R. Goodwin and Ann Harrer
Concrete International
45
Issue:
7
Efforts to streamline document information
SP-355_18
July 1, 2022
Renee T. Rios, Francesca Lolli, Katelynn Schoenrock, Kimberly E. Kurtis
355
Performance-based specifications (PBS) may increase concrete quality and sustainability by facilitating innovations in material selection and proportioning. This is particularly relevant now with increased interest in a broader set of minimally processed minerals for use as supplementary cementitious materials (SCMs) or fillers; these are often industrial and agricultural byproducts and with limited performance history in concrete. This study compares traditional largely prescriptive concrete design, following practices currently allowed by the Georgia Department of Transportation, with three new concrete designs which do not comply with current specifications but offer increased sustainability. Three metrics are assessed for each mixture: the associated cradle-to-gate CO2 emissions, a metric that incorporates the environmental burden of concrete, compressive strength at 28 days, and surface resistivity measurements taken weekly from 28 to 56 days. A framework is proposed to statistically analyze compressive strength data to pre-qualify mix designs, which can be broadly applied to reduce time-consuming iterative testing and to help meet sustainable development goals. The aim is to foster innovation in material use and mixture design towards an increased durability and performance, while reducing environmental impact and minimizing risk.
10.14359/51736027
CI4403HistoryExAwards
March 1, 2022
44
3
The inaugural ACI Excellence in Concrete Construction Award Gala was hosted at the fall ACI Concrete Convention in Denver, CO, USA, on November 9, 2015. The suggestion for the award program was made during one of the Institute’s chapter roundtables in February 2011 and was presented to the ACI Chapter Activities Committee at the Spring 2011 ACI Concrete Convention in Tampa, FL, USA.
Results Per Page 5 10 15 20 25 50 100
The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.