Title: Aggregate--The Decisiveelement in the Frost Resistance of Concrete

Author(s): G. V. Teodoru

Publication: Symposium Paper

Volume: 100

Issue:

Appears on pages(s): 1297-1310

Keywords: aggregates; compressive strength; concrete durability; freeze-thaw durability; tensile strength; General

DOI: 10.14359/3773

Date: 4/1/1987

Abstract:
The frost resistance of concrete is considerably influenced by aggregate. The aggregate must meet the conditions that are required in different specifications in regard to their mineralogical composition, grading curve, limit of fine particles, resistance to degradation (method with sodium sulfate), etc. The existing laboratory methods for testing the frost resistance of aggregates can only show the relative frost resistance of these; they cannot predict the performance of concrete made from these aggregates. It is necessary to test the response of concrete made from these aggregates to cycles of freezing. Experimentation was done to determine the influence of mineralogical structure, physical-chemical properties of aggregate, and their granulometric composition (especially the fine fraction). The influence of cement type and content and of admixture on the resistance of concrete to freezing was included. Investigations were done using measurements of the logarithmic decrement from the resonance curve as well as from the decay curve of the free vibrations. For comparison, the dynamic modulus of elasticity variation and the variations of strength in compression and tensile of concrete were used. The value of the logarithmic decrement is given, above which value the concrete is not resistant to frost damage.