Accelerated Mortar Bar Test Precision with Recycled Concrete Aggregate

2018 ◽  
Vol 115 (4) ◽  
Author(s):  
Bryce D. Fiore ◽  
Kenneth Gerow ◽  
Matthew P. Adams ◽  
Jennifer E. Tanner
Keyword(s):  
Recycled Concrete ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Accelerated Mortar Bar Test ◽  
Bar Test ◽  
Mortar Bar

scholarly journals Accelerated test methods for evaluating alkali-silica reactivity of recycled concrete aggregates

2021 ◽  
Author(s):  
Robert C Johnson
Keyword(s):  
Binding Capacity ◽  
Recycled Concrete ◽  
Test Duration ◽  
Accelerated Tests ◽  
Concrete Aggregates ◽  
Recycled Concrete Aggregates ◽  
Alkali Silica Reactivity ◽  
Accelerated Mortar Bar Test ◽  
Bar Test ◽  
Mortar Bar

This thesis reports the findings of a study carried out to determine the effectiveness of Accelerated Tests in evaluating the Alkali-Silica Reactivity of Recycled Concrete Aggregates. The study evaluated the variability of the Accelerated Mortar Bar Test due to test variables as well as the single and multi-laboratory variation. The variability of the Concrete Microbar Test due to test variables and the correlation to results from Accelerated Mortar Bar and Concrete Prism Test results were also evaluated. The tests were corroborated by comparing the porosity, permeability and alkali binding capacity of samples tested by the accelerated tests. It was found that the Accelerated Mortar Bar Test provides acceptable results when the test variables, such as crushing methods and absorption values, are carried out and evaluated properly. The Concrete Microbar Test was found to underestimate the expansion of reactive aggregates. However, the same test was found to provide good correlation to the expansion results of Concrete Prisms incorporating Supplementary Cementing Materials when the test duration was increased.

Applicability of the Accelerated Mortar Bar Test for Alkali-Silica Reactivity of Recycled Concrete Aggregates

2013 ◽  
Vol 2 (1) ◽  
pp. 20120030 ◽  
Author(s):  
Matthew P. Adams ◽  
Angela Jones ◽  
Sean Beauchemin ◽  
Robert Johnson ◽  
Benoit Fournier ◽  
...  
Keyword(s):  
Recycled Concrete ◽  
Concrete Aggregates ◽  
Recycled Concrete Aggregates ◽  
Alkali Silica Reactivity ◽  
Accelerated Mortar Bar Test ◽  
Bar Test ◽  
Mortar Bar

scholarly journals The Efficacy of Accelerated Test Methods to Evaluate Alkali Silica Reactivity of Recycled Concrete Aggregates

2021 ◽  
Author(s):  
Medhat Shehata ◽  
Robert Johnson
Keyword(s):  
Test Methods ◽  
Recycled Concrete ◽  
Accelerated Tests ◽  
Concrete Aggregates ◽  
Recycled Concrete Aggregates ◽  
Supplementary Cementing Materials ◽  
Alkali Silica Reactivity ◽  
Accelerated Mortar Bar Test ◽  
Bar Test ◽  
Mortar Bar

The effectiveness of accelerated tests in evaluating the Alkali-Silica Reactivity of Recycled Concrete Aggregates was evaluated. The Accelerated Mortar Bar Test was found effective for evaluating potential alkali-reactivity when the test variables, such as crushing method and absorption, are carried out in a well-defined process. The method of crushing was found to have significant impact on the expansion. The Concrete Microbar Test (CMBT) provides good correlation to the expansion of Concrete Prisms incorporating Supplementary Cementing Materials when an expansion limit of 0.10% at 56 days or 0.04% at 28 days were used, based on the limited number of tests carried out here.

scholarly journals The Efficacy of Accelerated Test Methods to Evaluate Alkali Silica Reactivity of Recycled Concrete Aggregates

2021 ◽  
Author(s):  
Medhat Shehata ◽  
Robert Johnson
Keyword(s):  
Test Methods ◽  
Recycled Concrete ◽  
Accelerated Tests ◽  
Concrete Aggregates ◽  
Recycled Concrete Aggregates ◽  
Supplementary Cementing Materials ◽  
Alkali Silica Reactivity ◽  
Accelerated Mortar Bar Test ◽  
Bar Test ◽  
Mortar Bar

The effectiveness of accelerated tests in evaluating the Alkali-Silica Reactivity of Recycled Concrete Aggregates was evaluated. The Accelerated Mortar Bar Test was found effective for evaluating potential alkali-reactivity when the test variables, such as crushing method and absorption, are carried out in a well-defined process. The method of crushing was found to have significant impact on the expansion. The Concrete Microbar Test (CMBT) provides good correlation to the expansion of Concrete Prisms incorporating Supplementary Cementing Materials when an expansion limit of 0.10% at 56 days or 0.04% at 28 days were used, based on the limited number of tests carried out here.

scholarly journals Accelerated test methods for evaluating alkali-silica reactivity of recycled concrete aggregates

2021 ◽  
Author(s):  
Robert C Johnson
Keyword(s):  
Binding Capacity ◽  
Recycled Concrete ◽  
Test Duration ◽  
Accelerated Tests ◽  
Concrete Aggregates ◽  
Recycled Concrete Aggregates ◽  
Alkali Silica Reactivity ◽  
Accelerated Mortar Bar Test ◽  
Bar Test ◽  
Mortar Bar

This thesis reports the findings of a study carried out to determine the effectiveness of Accelerated Tests in evaluating the Alkali-Silica Reactivity of Recycled Concrete Aggregates. The study evaluated the variability of the Accelerated Mortar Bar Test due to test variables as well as the single and multi-laboratory variation. The variability of the Concrete Microbar Test due to test variables and the correlation to results from Accelerated Mortar Bar and Concrete Prism Test results were also evaluated. The tests were corroborated by comparing the porosity, permeability and alkali binding capacity of samples tested by the accelerated tests. It was found that the Accelerated Mortar Bar Test provides acceptable results when the test variables, such as crushing methods and absorption values, are carried out and evaluated properly. The Concrete Microbar Test was found to underestimate the expansion of reactive aggregates. However, the same test was found to provide good correlation to the expansion results of Concrete Prisms incorporating Supplementary Cementing Materials when the test duration was increased.

Wadi gravel – a new concrete aggregate in Qatar: Part 2 –Alkali aggregate reactivity

2019 ◽  
Vol 53 (3) ◽  
pp. 400-412 ◽  
Author(s):  
Ian Sims ◽  
Khaled Hassan ◽  
Murray Reid ◽  
Mohammed bin Saif Al-Kuwari ◽  
Mohamed Attia ◽  
...  
Keyword(s):  
Perceived Risk ◽  
Test Methods ◽  
Petrographic Analysis ◽  
Concrete Aggregate ◽  
Gulf Region ◽  
Rock Types ◽  
Alkali Aggregate Reactivity ◽  
Accelerated Mortar Bar Test ◽  
Bar Test ◽  
Mortar Bar

Deposits of Wadi gravel are available in many parts of the Gulf region, but not widely utilized as aggregate for concrete, mainly due to the possibility of internal sulfate attack, plus the perceived risk of alkali aggregate reactivity (AAR). This paper describes the investigations for AAR of the Wadi gravel in this case, as part of the wider study described in Part 1 of this paper.Wadi gravel from the Mekaines site in Qatar was subjected to petrographic analysis, plus the gel-pat and accelerated mortar-bar test methods. The AAR potential was found to be low to normal. The accelerated mortar-bar test exhibited ‘innocuous’ behaviour after 14 days of immersion in alkali solution. When separately testing the constituent rock types of the Wadi gravel, limestone and quartz returned innocuous results, while rhyolite, granite and quartzite returned potentially alkali silica reactive (ASR) results and some reaction was confirmed using post-expansion petrographic examination.Wadi gravel was classified as potentially reactive in the RILEM AAR-4.1 accelerated concrete prism test, but of ‘low reactivity’ in the BS 812-123 test over the longer period of 12 months. Overcoming the potential problems of gypsum content and AAR successfully provides a valuable local resource of Wadi gravel aggregate for concrete.

scholarly journals Physical, Deformation, and Stiffness Properties of Recycled Concrete Aggregate

2021 ◽  
Vol 13 (8) ◽  
pp. 4245
Author(s):  
Katarzyna Gabryś ◽  
Emil Soból ◽  
Wojciech Sas
Keyword(s):  
Recycled Concrete ◽  
Experimental Program ◽  
Concrete Aggregate ◽  
Test Results ◽  
Recycled Concrete Aggregate ◽  
Granulometric Analysis ◽  
Stiffness Properties ◽  
Grain Distribution ◽  
Natural Aggregates ◽  
Critical Reduction

The construction sector is currently struggling with the reuse of waste originating from the demolition and modernization of buildings and roads. Furthermore, old buildings are gradually being replaced by new structures. This brings a significant increase of concrete debris to waste landfills. To prevent this, many studies on the possibilities of recycling concrete, known as recycled concrete aggregate (RCA), have been done. To broaden the applicability of reused concrete, an understanding of its properties and engineering behavior is required. A difficulty in sustainable, proper management of RCA is the shortage of appropriate test results necessary to assess its utility. For this reason, in the present study, the physical, deformation, and stiffness properties of RCA with gravely grain distribution were analyzed carefully in the geotechnical laboratory. To examine the mentioned properties, an extensive experimental program was planned, which included the following studies: granulometric analysis, Proctor and oedometer tests, as well as resonant column tests. The obtained research results show that RCA has lower values of deformation and stiffness parameters than natural aggregates. However, after applying in oedometer apparatus repetitive cycles of loading/unloading/reloading, some significant improvement in the values of the parameters studied was noticed, most likely due to susceptibility to static compaction. Moreover, some critical reduction in the range of linear response of RCA to dynamic loading was observed.

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