QUALITY SPECIFICATIONS OF CONCRETE MASONRY UNITS: A CASE STUDY OF THE INDUSTRIAL-ZONE IN AL-BAYDA CITY

Abstract

ABSTRACT

Concrete masonry units (CMUs) have been excessively produced in many factories inside Al-Bayda city in Libya, however the specifications of the produced CMUs are not yet investigated. A large number of concrete masonry unit factories are spreading out across the Industrial Zone of Al-Bayda city. All of the 14 factories located in the Industrial Zone were targeted to determine their CMU specifications. The American Society for Testing and Materials (ASTM) standard was used to determine how Al-Bayda CMU specifications measure up to the ASTM standard. The study focuses on the dimensions and permissible variations, density classification requirements, and strength requirements of units. The results showed that two factories out of the fourteen conformed to the ASTM C129 permissible variations of dimensions namely, factory I and N. All targeted factories produced units classified as normal weight except for factory B which produced units with medium weight. The net area compressive strength data showed that all of the 14 factories produce a nonloadbearing CMU type. Eleven factories out of fourteen failed to meet the minimum compressive strength standard specification of 4.14 MPa. Only three factories passed the compressive strength test, namely I, M and D. The overall conclusion in this study case was that all 14 factories have failed to meet one or more of the specifications required by the ASTM standards.