Scope and Applicability
- Applies to all Portland cement purchased by the Commonwealth government for public construction projects.
- Intended to ensure durability and economy in government infrastructure through appropriate cement standards.
Specifications for Portland Cement
- Portland cement must conform to the US Federal Specification SS-C-192 dated October 14, 1930.
- The temperature for testing is adjusted from 21°C (70°F) to 27°C (80.6°F) to suit local Philippine climatic conditions.
Requirements for High-Silica Content Cement
- Recommended for certain public works to improve durability.
- Must be produced by inter-grinding Portland cement clinker with pozzolanic material having not less than 50% silica.
- Pozzolanic material must be dehydrated and calcined appropriately prior to grinding.
- Gypsum may be added before or during grinding.
Chemical Composition Limits for High-Silica Cement
- Loss on ignition: not to exceed 5.00%.
- Sulphuric anhydride (SO3): not to exceed 2.00%.
- Magnesia (MgO): not to exceed 5.00%.
Physical Properties and Quality Control
- Fineness: at least 85% of the cement must pass through a 325-mesh standard sieve.
- Tensile Strength:
- Average tensile strength of three standard mortar briquettes (1 part cement to 3 parts Ottawa sand by weight) must meet:
- 300 psi at 7 days (after 1 day moist air and 6 days water storage).
- 400 psi at 28 days (after 1 day moist air and 27 days water storage).
- No retrogression in tensile strength between 7 and 28 days is allowed.
- Average tensile strength of three standard mortar briquettes (1 part cement to 3 parts Ottawa sand by weight) must meet:
Repeal of Previous Orders
- Executive Orders No. 75 (1912), No. 19 (1918), and No. 367 (1932) are repealed.
Legal Authority and Promulgation
- Issued by President Manuel L. Quezon under existing legal powers.
- Signed and promulgated in Manila on August 30, 1937.
- Countersigned by Secretary Elpidio Quirino.