9. Provided that no hollow concrete building blocks shall be used in the construction of any building in the city of Philadelphia, unless the maker of said blocks has submitted his product to the full test required by the Bureau of Building Inspection and placed on file with said Bureau of Building Inspection a certificate from a reliable testing laboratory showing that samples from the lot of blocks to be used have successfully passed the requirements of the Bureau of Building Inspection, and filing a full copy of the test with the bureau.
10. A brand or mark of identification must be impressed in or otherwise permanently attached to each block for purpose of identification.
11. No certificate of approval shall be considered in force for more than four months unless there be filed with the Bureau of Building Inspection, in the city of Philadelphia, at least once every four months following, a certification from some reliable physical testing laboratory showing that the average of three (3) specimens tested for compression and three (3) specimens tested for transverse strength comply with the requirements of the Bureau of Building Inspection of the city of Philadelphia, said samples to be selected either by a building inspector or by the laboratory from blocks actually going into construction work. Samples must not be furnished by the contractors or builders.
12. The manufacturer and user of any such hollow concrete blocks as are mentioned in this regulation, or either of them, shall at any time have made such tests of the cements used in making such blocks or such further tests of the completed blocks, or of each of these, at their own expense, and under the supervision of the Bureau of Building Inspection, as the chief of said bureau shall require.
13. The cement used in making said blocks shall be Portland cement, and must be capable of passing the minimum requirements as set forth in the " Standard Specifications for Cement " by the American Society for Testing Materials.
14. Any and all blocks, samples of which, on being tested under the direction of the Bureau of Building Inspection, fail to stand at twenty-eight days the tests required by this regulation, shall be marked condemned by the manufacturer or user and shall be destroyed.
15. No concrete blocks shall be used in the construction of any building within the city of Philadelphia until they shall have been inspected and average samples of the lot tested, approved and accepted by the chief of the Bureau of Building Inspection.
1. These regulations shall apply to all new materials such as are used in building construction, in the same manner and for the same purposes, as stones, brick, concrete, are now authorized by the building laws, when said new material to be substituted departs from the general shape and dimensions of ordinary building brick, and more particularly to that form of building material known as hollow concrete block manufactured from cement and a certain addition of sand, crushed stone or similar material.
2. Before any such material is used in buildings an application for its use and for a test of the same must be filed with the chief of the Bureau of Building Inspection. A description of the material and a brief outline of its manufacture and proportions of the materials used must be embodied in the application.
3. The material must be subjected to the following tests: Transverse, compression, absorption, freezing and fire. Additional tests may be called for when, in the judgment of the chief of the Bureau of Building Inspection, the same may be necessary. All such tests must be made in some laboratory of recognized standing, under the supervision of the engineer of the Bureau of Building Inspection. The tests will be made at the expense of the applicant.
4. The results of the tests, whether satisfactory or not, must be placed on file in the Bureau of Building Inspection. They shall be open to inspection upon application to the chief of the bureau, but need not necessarily be published.
5. For the purposes of the tests at least twenty (20) samples or test pieces must be provided. Such samples must represent the ordinary commercial product. They may be selected from stock by the chief of the Bureau of Building Inspection or his representative, or may be made in his presence, at his discretion. The samples must be of the regular size and shape used in construction. In cases where the material is made and used in special shapes and forms too large for testing in the ordinary machines, smaller-sized specimens shall be used as may be directed by the chief of the Bureau of Building Inspection, to determine the physical characteristics specified in Section 3.
6. The samples may be tested as soon as desired by the applicant, but in no case later than sixty days after manufacture.
7. The weight per cubic foot of the material must be determined.
8. Tests shall be made in series of at least five, except that in the fire tests a series of two (four samples) are sufficient. Transverse tests shall be made on full-sized samples. Half samples may be used for the crushing, freezing, and fire tests. The remaining samples are kept in reserve, in case unusual flaws or exceptional or abnormal conditions make it necessary to discard certain of the tests. All samples must be marked for identification and comparison.
9. The transverse tests shall be made as follows: The samples shall be placed flatwise on two rounded knife-edge bearings set parallel, seven inches apart. A load is then applied on top, midway between the supports, and transmitted through a similar rounded knife edge until the sample is ruptured. The modulus of rupture shall then be determined by multiplying the total breaking load in pounds by 21 (three times the distance between supports in inches), and then dividing the result thus obtained by twice the product of the width in inches by the square of the depth in inches.