Using of Waste Materials to Stabilize Expansive Clay for Airport Rigid Pavement

Rigid pavement rested on clayey soil may be adversely affected by the behavior of sub-grade soil. The clayey soil may swell or shrink which causes unexpected cracks in pavement and therefore needs greater thickness to sustain the expected loads. The objective of this study is to achieve an economic design of rigid pavement on expansive clay. Specimens of reinforced concrete slabs were tested on a bed of Egyptian soil and were loaded until failure. Firstly, a reinforced concrete slab supported on a well compacted natural soil was tested to sustain the expected traffic loads without any additives. Secondly, improve the sub-grade soil under the rigid pavement using ground granulated blast furnace slag, cement dust, and lime. Thirdly, improve the sub-grade soil under the rigid pavement using ground granulated blast furnace slag (GGBS), cement dust (CD), and lime (L) stabilizers. Fourthly, replace the expansive soil (ES) using sand layer Firstly, improve the in-situ materials by normal compaction methods and design for the modified properties to sustain the expected traffic loads without any additives. Secondly, improve the sub-grade soil under the rigid pavement using ground granulated blast furnace slag (GGBS), cement dust (CD), and lime (L). Thirdly, improve the sub-grade soil under the rigid pavement using ground granulated blast furnace slag (GGBS), cement dust (CD), and lime (L) stabilizers. Fourthly, replace the expansive soil (ES) using sand layer. The results of this study proved that the best alternative to obtain the best stress / strain ratio was using GGBS and lime (31 ratio) to stabilize the natural soil and the percentage of total binder was 6 % by dry weight of soil.