Class (1) Fill
Class 1 fill is a crusher run type material normally used as a road base. It shall be good, hard well-graded material screened and crushed as necessary to lie within the grading envelope given below when tested. The fill material shall be non-plastic when tested and the content of clay and friable particles when determined, shall not exceed 1% for any individual sieve size fraction. The total sulfate content as SO3 of the material shall not exceed 1% and the total soluble salts shall not exceed 2%. When used as road base, CBR at 95% max. Dry density should be minimum 80%.
Class (2 Fill)
Class 2 fill is normally employed as a road sub-base material and shall be good, hard well-graded material, screened and crushed as necessary to lie within the grading envelope given below when tested. The CBR of the material when tested at the density likely to exist in the field shall not be less than 30%. The liquid limit shall not be more than 25% and the plasticity index shall not exceed 6% when tested. The total soluble salts shall not exceed 2%.
Class 3 Fill (Desert Fine)
Class 3 fill is desert fill type material and shall be a selected, graded, hard granular material free from clay and deleterious substances. The total sulphate content as SO3 of the material shall not exceed 1% and the total soluble salts shall not exceed 2%.
The grading of the fill shall lie within the grading envelope given below when tested. Where the percentage passing the 0.075mm sieve is greater than 8%, the plasticity index shall not exceed 20%.
Class 4 (Dredged Marine Sand)
Class 4 fill is a dredged sand type material normally employed as common fill. The material shall be evenly graded and shall lie within the grading envelope given below when tested. The material shall be non-plastic when tested. The total sulphate content as SO3 of the material shall not exceed 1% and the total soluble salts shall not exceed 2%.
Class 5 Fill (Drainage Fill)
Class 5 fill is a single size-type material normally employed as drainage blanket medium. The material shall be good hard rock screened and crushed to lie within the grading envelope shown below and shall be free from deleterious material.
Class 6 (Crusher Dust/Fines)
Class 6 fill is a crusher dust type material. It shall be good, hard rock screened and crushed to lie within the grading envelope shown below and free from natural sand, silt, clay and any other deleterious material. Class 6 fill shall also be non-plastic when tested and shall not be susceptible to breakdown under moist conditions.
The total sulphate content as SO3 of the material shall not exceed 1%and the total soluble salts shall not exceed 2%.
Class 7 (Hardcore)
Class 7 is a hardcore material. It shall be good stone, concrete, hard tiles or other approved material not exceeding 100mm gauge with not more than 1% passing a 20mm sieve. The fill shall not be susceptible to breakdown under moist conditions and shall not contain any deleterious materials. The total sulphate content as SO3 of the material shall not exceed 1% and the total soluble salts shall not exceed 2%.