PRESCRIBING SPECIFICATIONS FOR PORTLAND CEMENT

Upon the recommendation by the Director of Public Works and the Secretary of Public Works and Communications that high-silica content cement be used for certain classes of public works in order to effect durability and economy, I, Manuel L. Quezon, President of the Philippines, by virtue of the powers vested in me by law, do hereby order that all Portland cement that may hereafter be purchased by the Government of the Commonwealth of the Philippines for use in construction work to be done by or for the Government shall conform in every respect to the revised specification for Portland cement, as published in Circular Numbered Thirty-three of the Bureau of Standards, United States Department of Commerce and Labor, issued January eighteenth, nineteen hundred and seventeen, and known as the United States Government specification for Portland cement: Provided, however, That, to meet local climatic conditions by reason of the fact that it will be necessary to make tests at a somewhat a higher temperature than twenty-one degrees centigrade (seventy degree Fahrenheit), twenty-seven degrees centigrade (eighty and six-tenths degrees Fahrenheit) shall be substituted for the temperature given in said revised specification: And provided, further, That high-silica content Portland cement that may be used by the Government shall also comply with the following requirements:

(1) The cement shall be the product obtained by inter-grinding Portland cement clinker with a pozzolanic material containing not less than fifty percent of silica, the pozzolanic material having been previously dehydrated and calcined at a suitable temperature. The requisite amount of gypsum may be added before or during the grinding operation.

(2) Chemical composition:

The following limits shall not be exceeded:

	Percent
Loss on ignition	5.00
Sulfuric anhydride	2.00
Magnesia	5.00

(3) Fineness:

At least eighty-five percent shall pass a standard three hundred twenty-five-mesh sieve.

(4) Tensile strength:

The average tensile strength in pounds per square inch of not less than three standard mortar briquettes composed of one part of cement and three parts of standard Ottawa sand, by weight, shall be equal to or higher than the following:

Age at test		Tensile strength
days	Storage of briquettes	pounds
7	One day in moist air, 6 days in water	300
28	One day in moist air, 27 days in water	400

There shall be no retrogression in strength from seven to twenty-eight days.

Executive Order Numbered Seventy-five, series of nineteen hundred and twelve, and Executive Order Numbered Nineteen hundred and eighteen, are hereby repealed.

Done at the City of New York, U.S.A. (for the City of Manila), this fourteenth day of June, in the year of Our Lord, nineteen hundred and thirty-seven, and of the Commonwealth of the Philippines, the second.

By the President:

(Sgd.) ELPIDIO QUIRINO
Secretary of the Interior