Final Report on Durability Project, Michigan Test Road

Built in conjunction with the Design Project in 1940, the Durability Project of the Michigan Test Road was designed to study the effect of various factors on the durability of concrete in service. the study included both materials and operations, principally the following factors: (1) proportioning and grading of aggregates; (2) various types of additives, including plasticizers and air-entraining agents; (3) blends of portland with natural cement produced with and without a grinding aid; (4) limestone aggregates in various combinations and gradings; and (5) finishing and curing. The most outstanding result was the early verification of the beneficial effect of air entrainment on the durability of concrete, which led to the decision in 1943 to use air-entrained concrete in all Michigan pavements.