Chapter 6: Local Road Construction Management 173 checked by Materials Engineer through FDT, field CBR if necessary or by the laboratory according to DPWH testing procedures; and iii. The tolerance on the formation level should be in accordance to the technical specifications. The finished work should lie between these limits and should be checked jointly between the Site Inspector and the Contractor. Should the tolerance be exceeded the Contractor shall remove, replace and recompact the sub-base material or lay a thicker layer of base-course at contractors expense. b. Base Preparation i. Material • The Materials Engineer should ensure that all materials are within the Specification and passed the required testing, should also ensure the Site Inspector that the stockpile is approved before permitting the Contractor to use it; and • The site staff should look out for segregation if stockpiles of material are allowed to dry out. Any segregated materials will not have the strength required and must be remixed and gradation re-checked. ii. Spreading and Compacting • Sub-base is normally spread from tipped piles by grader or spreader box. Again, attention should be given that no segregation takes place; • Compaction of sub-base is by the end result method. However, attention is drawn to the requirements of Specifications. Trial Sections whereby the Contractor must demonstrate his proposals for materials and equipment meet the requirements of the Contract; • Attention is also drawn to Spreading and Compaction wherein the field density must conform to what was stated in the specifications;