Miniature Concrete Prism Test: Rapid Test Method for Evaluating Alkali-Silica Reactivity of Aggregates

Alkali-silica reaction (ASR) is one of the most significant durability issues in concrete structures. Although there are a number of standardized test procedures to evaluate the aggregate reactivity, each method has its own drawbacks. Two of the most common tests that are employed widely are the accelerated mortar bar test (AMBT) (ASTM C1260) and the concrete prism test (CPT) (ASTM C1293). The major issue with the AMBT test is the number of false-positive results from this test associated with high test temperature, rendering the test method unreliable. CPT is one of the most reliable tests for assessing the potential for ASR, but its major disadvantage is the duration of the test involved, which takes one to two years. In this research, a novel test method called the miniature concrete prism test (MCPT) was developed and the effectiveness and reliability of the results assessed when compared with CPT and AMBT. Samples of 26 coarse aggregates and 16 fine aggregates with various reactivity levels were employed for the testing. The test results were compared for MCPT versus CPT, in which 23 out of 26 coarse aggregates and eight out of 16 fine aggregates either passed or failed in both MCPT and CPT. For MCPT versus AMBT, 16 out of 26 coarse aggregates and 13 out of 16 fine aggregates either passed or failed in both MCPT and AMBT. The sensitivity of false-negative and false-positive aggregate sources is discussed and explained briefly.

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Assessment of Alkali–Silica Reactivity of Aggregates by Concrete Expansion Tests in Alkaline Solutions at 38 °C

Materials ◽

10.3390/ma13020288 ◽

2020 ◽

Vol 13 (2) ◽

pp. 288 ◽

Cited By ~ 1

Author(s):

Irene Bavasso ◽

Umberto Costa ◽

Teresa Mangialardi ◽

Antonio Evangelista Paolini

Keyword(s):

Field Performance ◽

Test Method ◽

Alkaline Solutions ◽

Test Duration ◽

Simplified Approach ◽

Concrete Prism ◽

Expansion Test ◽

Alkali Silica Reactivity ◽

Natural Aggregates ◽

Pore Liquid

A new accelerated concrete prism expansion test at 38 °C (accelerated CPT) is proposed for assessing the alkali-reactivity of concrete aggregates. In this test, concrete prisms with a standardized mix composition and different alkali contents are immersed in alkaline solutions with compositions simulating the pore liquid of hardened concretes. The concrete prism expansion test at 38 °C and RH > 95% (traditional CPT) was taken as a reference test, in order to define the appropriate expansion limit criterion for the proposed accelerated CPT. Three natural aggregates of known field performance and different alkali–silica reactivity were tested. The compositions of alkaline solutions were designed by assuming total dissolution of cement alkalis and taking a ratio between the mass fractions of effective water consumed by cement hydration and of alkalis uptaken by cement hydrates equal to unity. This simplified approach was found in an acceptable agreement with literature empirical equations correlating pore solution alkalinity of hardened Portland cement mixes with total alkali content of cement. Elaboration of expansion data through both pass-fail and threshold alkali level (TAL)-evaluation approaches indicated that, for the accelerated CPT, an expansion limit criterion of 0.04% after 120 days of testing in alkaline solutions is appropriate to evaluate the aggregate alkali reactivity congruently with the traditional CPT. Use of the proposed test method in place of the traditional CPT would reduce the test duration from 365 to 120 days.

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Development of Enhanced Test Methods to Evaluate Alkalisilica Reaction in Concrete

10.32920/ryerson.14651913 ◽

2021 ◽

Author(s):

Noura Sinno

Keyword(s):

Preventive Measures ◽

Test Methods ◽

Standard Test ◽

Test Method ◽

The Other ◽

Field Conditions ◽

Alkali Silica Reaction ◽

Test Duration ◽

Concrete Prism ◽

Concrete Prism Test

Many preventive measures showed improved performance of concrete against alkali-silica reaction (ASR) based on the concrete prism test (CPT) described in the Canadian and American Standards, CSA A23.2-14A and ASTM C1293. However, research has shown that preventive measures that limited the 2-year expansion in the concrete prism test produced late expansion after 7-15 years when tested in the field. The objective of this research is to understand the possible reasons for this late expansion under field conditions and to come up with modified approach to determine the level of supplementary cementing materials (SCM) needed to mitigate the long-term expansion. The research mainly focuses on studying two possible reasons to explain the late expansion. The first reason is the rate and ultimate hydration of SCM, where their capacity to bind alkalis under CPT could be higher than those under field conditions. The other reason for the late expansion could be the geometry and size of the CPT samples which might reduce the expansion due to the excessive alkali leaching. Larger samples showed less leaching compared to standard prisms. 100-mm cylinders showed higher expansion than 75-mm standard prisms; however, both sample shapes showed similar expansions for one tested aggregate when used with SCM. In addition, the capacity of SCM to bind alkalis was shown to be higher at 38ºC compared to the other two tested temperatures investigated in this study: 23ºC and 60ºC. Samples with SCM at high replacement levels expanded more at 60ºC compared to 38ºC. Due to their reduced leaching compared to prisms, testing cylinders at 60ºC showed accelerated results reducing the testing duration to one year compared to the standard test duration of two years. Moreover, a new way to predict the minimum levels of SCM required to mitigate expansion due to alkali-silica reaction is presented showing better correlation with the field. Finally, a fast and reliable test method is suggested to evaluate the reactivity of mineral fillers by adapting and adopting the current test methods available for ASR testing.

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Development of Enhanced Test Methods to Evaluate Alkalisilica Reaction in Concrete

10.32920/ryerson.14651913.v1 ◽

2021 ◽

Author(s):

Noura Sinno

Keyword(s):

Preventive Measures ◽

Test Methods ◽

Standard Test ◽

Test Method ◽

The Other ◽

Field Conditions ◽

Alkali Silica Reaction ◽

Test Duration ◽

Concrete Prism ◽

Concrete Prism Test

Many preventive measures showed improved performance of concrete against alkali-silica reaction (ASR) based on the concrete prism test (CPT) described in the Canadian and American Standards, CSA A23.2-14A and ASTM C1293. However, research has shown that preventive measures that limited the 2-year expansion in the concrete prism test produced late expansion after 7-15 years when tested in the field. The objective of this research is to understand the possible reasons for this late expansion under field conditions and to come up with modified approach to determine the level of supplementary cementing materials (SCM) needed to mitigate the long-term expansion. The research mainly focuses on studying two possible reasons to explain the late expansion. The first reason is the rate and ultimate hydration of SCM, where their capacity to bind alkalis under CPT could be higher than those under field conditions. The other reason for the late expansion could be the geometry and size of the CPT samples which might reduce the expansion due to the excessive alkali leaching. Larger samples showed less leaching compared to standard prisms. 100-mm cylinders showed higher expansion than 75-mm standard prisms; however, both sample shapes showed similar expansions for one tested aggregate when used with SCM. In addition, the capacity of SCM to bind alkalis was shown to be higher at 38ºC compared to the other two tested temperatures investigated in this study: 23ºC and 60ºC. Samples with SCM at high replacement levels expanded more at 60ºC compared to 38ºC. Due to their reduced leaching compared to prisms, testing cylinders at 60ºC showed accelerated results reducing the testing duration to one year compared to the standard test duration of two years. Moreover, a new way to predict the minimum levels of SCM required to mitigate expansion due to alkali-silica reaction is presented showing better correlation with the field. Finally, a fast and reliable test method is suggested to evaluate the reactivity of mineral fillers by adapting and adopting the current test methods available for ASR testing.

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Corrosion of metals in wood: Comparing the results of a rapid test method with long-term exposure tests across six wood treatments

Corrosion Science ◽

10.1016/j.corsci.2011.01.039 ◽

2011 ◽

Vol 53 (5) ◽

pp. 1708-1714 ◽

Cited By ~ 14

Author(s):

Samuel L. Zelinka ◽

Donald S. Stone

Keyword(s):

Rapid Test ◽

Test Method

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A rapid test method for evaluating the tracking and erosion resistance of polymeric outdoor insulating materials

IEEE 1997 Annual Report Conference on Electrical Insulation and Dielectric Phenomena ◽

10.1109/ceidp.1997.641096 ◽

2002 ◽

Cited By ~ 7

Author(s):

R. Gorur ◽

J. Montesinos ◽

L. Varadadesikan ◽

S. Simmons ◽

M. Shah

Keyword(s):

Erosion Resistance ◽

Rapid Test ◽

Test Method ◽

Insulating Materials

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Effect of sample geometry and aggregate type on expansion due to alkali-silica reaction

10.32920/16732957 ◽

2021 ◽

Author(s):

Noura Sinno ◽

Medhat Shehata

Keyword(s):

Alkali Silica Reaction ◽

Sample Geometry ◽

Concrete Prism ◽

Supplementary Cementing Materials ◽

Field Samples ◽

Alkali Leaching ◽

Concrete Prism Test ◽

Cylindrical Samples

Late expansions due to alkali-silica reaction were observed in field samples for some aggregates and supplementary cementing materials (SCM) combinations despite meeting the 2-year expansion criterion of the concrete prism test. This fosters a research into the effect of sample geometry and aggregate reactivity on alkali leaching and expansion of lab samples. Larger samples showed less leaching compared to standard prisms. Cylinders of 100 mm-diameter showed higher expansion than 75 mm-standard prisms; however, both sample shapes showed similar expansions for one tested aggregate when used with SCM. Alkali leaching from concrete samples and alkali release from some aggregates could lead to cylindrical samples having higher expansion and better correlation to field samples compared to standard concrete prisms.

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