Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Mitigation of Alkali-Silica Reactivity in New Concrete in New Hampshire Phase 2
A Phase 2 research study was undertaken to identify the types and amounts of admixture(s) needed to reduce Alkali-silica reactivity (ASR) expansion in new concrete made with reactive New Hampshire aggregates. The Phase 1 study found that twenty-five percent of the New Hampshire concrete aggregates tested under ASTM C1260-94 are potentially reactive (0.1% or greater elongation at 14 days) and identified ASR in over 40 percent of the concrete cores taken from existing bridge structures throughout the state. The objectives of the Phase 2 research were the following: Evaluate different admixtures for their effectiveness in mitigating the development of ASR in new concrete in New Hampshire through ASTM C1260-94 accelerated mortar bar testing; Verify the minimum amounts of admixture(s) needed to reduce ASR expansion (to less than 0.1% at 14 days) in new concrete made with reactive NH aggregates; Evaluate both mineral and chemical admixture(s) to include Fly Ash, Ground Granulated Blast Furnace Slag (GGBF) and Silica Fume; Evaluating the ability of blended cement, ternary cement and high-reactivity metkaolin (HRM) to control expansion due to alkali-silica reaction (ASR); Conduct petrographic thin section analysis on mortar bars of selected Portland Cement Concrete (PCC) mixes to confirm the mitigation of Alkali-Silica Reactivity at the microscopic level. The Phase 2 research utilized the ASTM C1260-94 accelerated mortar bar test to identify the amounts of admixture(s) needed to reduce expansion in new concrete in New Hampshire to less than 0.1% elongation at 14 days. Several of the more highly reactive concrete aggregates in New Hampshire were utilized in the PCC mixes for the mortar bars. The research demonstrated that both chemical and mineral admixtures(s), some combinations of admixtures, blended cement, ternary cement and high reactivity met kaolin (HRM) all have the ability to control (less than 0.1% elongation at 14 days) Alkali-Silica Reactivity in new concrete made with New Hampshire reactive aggregates. The development of ASR was not effectively mitigated with the admixture of silica fume when utilizing the ASTM C1260-94 test method. Petrographic thin section analysis on mortar bars from selected PCC mixes confirmed the ability of these products to mitigate the development of Alkali-Silica Reactivity (ASR).
Mitigation of Alkali-Silica Reactivity in New Concrete in New Hampshire Phase 2
A Phase 2 research study was undertaken to identify the types and amounts of admixture(s) needed to reduce Alkali-silica reactivity (ASR) expansion in new concrete made with reactive New Hampshire aggregates. The Phase 1 study found that twenty-five percent of the New Hampshire concrete aggregates tested under ASTM C1260-94 are potentially reactive (0.1% or greater elongation at 14 days) and identified ASR in over 40 percent of the concrete cores taken from existing bridge structures throughout the state. The objectives of the Phase 2 research were the following: Evaluate different admixtures for their effectiveness in mitigating the development of ASR in new concrete in New Hampshire through ASTM C1260-94 accelerated mortar bar testing; Verify the minimum amounts of admixture(s) needed to reduce ASR expansion (to less than 0.1% at 14 days) in new concrete made with reactive NH aggregates; Evaluate both mineral and chemical admixture(s) to include Fly Ash, Ground Granulated Blast Furnace Slag (GGBF) and Silica Fume; Evaluating the ability of blended cement, ternary cement and high-reactivity metkaolin (HRM) to control expansion due to alkali-silica reaction (ASR); Conduct petrographic thin section analysis on mortar bars of selected Portland Cement Concrete (PCC) mixes to confirm the mitigation of Alkali-Silica Reactivity at the microscopic level. The Phase 2 research utilized the ASTM C1260-94 accelerated mortar bar test to identify the amounts of admixture(s) needed to reduce expansion in new concrete in New Hampshire to less than 0.1% elongation at 14 days. Several of the more highly reactive concrete aggregates in New Hampshire were utilized in the PCC mixes for the mortar bars. The research demonstrated that both chemical and mineral admixtures(s), some combinations of admixtures, blended cement, ternary cement and high reactivity met kaolin (HRM) all have the ability to control (less than 0.1% elongation at 14 days) Alkali-Silica Reactivity in new concrete made with New Hampshire reactive aggregates. The development of ASR was not effectively mitigated with the admixture of silica fume when utilizing the ASTM C1260-94 test method. Petrographic thin section analysis on mortar bars from selected PCC mixes confirmed the ability of these products to mitigate the development of Alkali-Silica Reactivity (ASR).
Mitigation of Alkali-Silica Reactivity in New Concrete in New Hampshire Phase 2
R. M. Lane (Autor:in) / M. C. Fish (Autor:in)
2005
26 pages
Report
Keine Angabe
Englisch
Mitigation of Alkali-Silica Reactivity in New Mexico
| British Library Online Contents | 2000
Mitigation of Alkali-Silica Reactivity in New Mexico
| British Library Conference Proceedings | 2000
Alkali-silica reactivity criteria for concrete aggregates
| Online Contents | 2005
Alkali-silica reactivity criteria for concrete aggregates
| Springer Verlag | 2005