TRIS Online Record

Printable View

Title	NEW HAMPSHIRE'S CONCRETE AGGREGATE AND ALKALI-SILICA REACTIVITY - STATEWIDE ASSESSMENT OF FINE AND COARSE CONCRETE AGGREGATE
Accession No	00942592
Authors	Lane, R M; Fish, M F
Corp. Authors / Publisher	New Hampshire Department of Transportation ; Federal Highway Administration
Publication Date	20021202
Description	47 p.; Appendices(3); Figures; Photos; References(9); Tables
Languages	English
Abstract	Alkali-silica reactivity (ASR) has become a major concern with regards to long-term durability of concrete structures in New Hampshire. Many concrete structures built by the New Hampshire Department of Transportation (NHDOT) show visible distress. The cause of this distress has been suspected to be deleterious ASR expansion or other destructive processes in conjunction with ASR. Verification of an association between ASR and visual observations of deterioration within the structures has not been done. The objectives of this research were the following: determine the potential for the development of ASR in concrete using fine and coarse aggregates in New Hampshire; confirm the presence and extent of ASR in existing NHDOT concrete structures; identify the types of rocks in New Hampshire that are potentially reactive; and evaluate the need for an additional study to determine the amount of admixtures required for the minimization of ASR in new concrete within New Hampshire. The research demonstrated that a significant number of the concrete aggregates within New Hampshire are potentially reactive (0.1% or greater elongation at 14 days). The presence of ASR within the laboratory constructed mortar bars made with potentially reactive aggregates was confirmed through petrographic thin section analysis. ASR gel was also confirmed within selected concrete bridges through uranyl acetate UV-light testing as well as core sampling and petrographic thin section analysis. Based on the research findings a Phase 2 study is recommended which would evaluate different admixtures for their effectiveness in mitigating the development of ASR in new concrete.
TRT Terms	Admixtures ; Alkali silica reactions ; Concrete aggregates ; Concrete structures ; Cores (Specimens) ; Deterioration ; Durability ; Laboratory tests ; Petrography ; Reactive aggregates
Geographical Terms	New Hampshire
Subject Areas	I36 Aggregates; H32 CEMENT AND CONCRETE; I32 Concrete; H35 MINERAL AGGREGATES
Contract Number	SPR-0004(17)
Report Number	FHWA-NH-RD-12323N,; Final Report
Availability	National Technical Information Service
TRIS Files	HRIS
Database	TRIS Online