PRECAST CONCRETE MANHOLES
design specifiions. ASTM C478: OVERVIEW PART I The concrete constituents shall conform to the applicable ASTM Standards. Minimum compressive strength shall be 4,000 psi. • Maximum watercementitious ratio of specified. • A typical precast wetcast mix has a w/c ratio of – • A typical precast drycast mix has a w/c ratio of – • Cement – ASTM C150 ...