Author

Dr. Aref Al-Sawidani.

Published in

13TH Arab Structural Engineering Conference University of BLIDA 1 December 13-15, 2015 ALGERIA.

Abstract

Basaltic rocks are used extensively as engineering materials including aggregates for Portland cement concrete and asphalt concrete. Syria is very rich in Basaltic rocks. There are reserves estimated to be several billion tonnes according to recent geological investigations. The annual production of concrete in Syria is about 20 million m3, containing about 35 million tonnes of aggregates. Due to some concerns, use of basalt as concrete aggregate is very limited in Syria. One of the most important concerns is the risk of the alkali-silica reaction. The objective of this paper is to report a part of an ongoing research on the influence of using crushed basalt as aggregates on one of durability related properties of concrete (i.e. alkali-silica reaction which is the most common form of Alkali-Aggregate Reaction).

Alkali resistance has been investigated through several methods specified in the American Standards. Results of petrographic examination, chemical test (ASTM C289) and accelerated mortar bar test (ASTM C1260) have been particularly reported. In addition, the weight loss and compressive strength of 28 days cured concrete containing basaltic aggregates were also reported after 90 days of exposure to 10% NaOH solution. Dolomite aggregate were used in the latter test for comparison. The experimental results revealed that basaltic rocks quarried from As-Swaida’a region (at about 100 km southeast of Damascus) were suitable for production of aggregates for concrete. According to the test results, the studied basalt aggregates can be classified as innocuous from the alkali-silica reaction’ point of view.

Further, the 10% sodium hydroxide attack didn’t affect the mechanical properties of concrete.

Key words: alkali attack, basalt aggregate, durability, alkali-silica reaction