Sand-Cement Bed. - Upon the concrete foundation shall be spread a layer of mortar one inch in thickness and made of one part of Portland cement, and three parts of sand. Only sufficient water shall be added to this mixture to insure a proper setting of the cement, the intention being to produce a granular mixture which may be raked to the desired grade. The sand and cement shall be thoroughly mixed and shall be spread in place on the foundation immediately in advance of the brick laying to such a thickness that when the brick are set and properly bedded in the bed, their tops shall conform accurately to the finished grade of the roadway. The concrete foundation shall be cleaned and swept and shall be thoroughly dampened immediately in advance of placing the sand-cement bed. The mortar bed shall be struck by templates to a surface parallel to the grade and contour of the finished pavement.

Laying the Brick. - The brick shall be laid in straight line on edge, at right angles to the curb. At intersections they shall be laid as directed. Brick shall be laid with the ends and sides close together and with the lug sides all in the same direction. Joints shall be broken by at least three (3) inches. At every fourth course the brick shall be driven together to secure contact and straight courses, and all thick brick shall be removed. Brick shall be laid with the better side up.

When any section shall contain more than ten (10) per cent. of culls, the brick shall be taken up and the cushion adjusted. Brick shall be laid from curb to curb or car track to curb.

No bats or broken brick shall be used except at curbs or at street car tracks. Brick so broken for batting shall be cut square with the top and sides of the brick. Batting for closures shall immediately follow the laying. All joints must be kept clean and open to the bottom until filled as specified. In batting, no piece less than three (3) inches shall be used.

Rolling. - After the brick in the pavement have been accepted for rolling and the surface swept clean, the pavement shall be rolled with a roller weighing not less than five (5) nor more than seven (7) tons, in the following manner: The brick next the curb shall be tamped with a hard wood tamper, to the proper grade. The rolling shall then commence near the curb at a very slow pace, and continue back and forth toward the center, until the center of the street is reached; then, passing to the opposite curb, it shall be repeated in the same manner to the center of the street. After this first passing of the roller the pace may be quickened and the rolling continued until each brick is firmly embedded in the bed. The pavement shall then be rolled transversely at an angle of forty-five (45) degrees from curb to curb, repeating the rolling in the opposite forty-five degree direction. Before and after this transverse rolling has taken place, all broken or injured brick must be taken up, and replaced with perfect ones. The brick substituted must be brought to the true surface by tamping.

After final rolling the pavement shall be tested with a ten (10) foot straightedge, laid parallel with the curb, and any depression exceeding one-quarter (1/4) of an inch must be remedied. If necessary, the pavement shall be again rolled.

If a sand-cement bed is used the rolling as above specified must be done before the cement has taken its initial set; in general, it will be required that the rolling be done at least twice a day and oftener if deemed necessary by the Engineer.

A short time before the rolling is commenced the pavement shall be thoroughly sprayed so that sufficient water enters the sand-cement bed to thoroughly set the cement. If any of the sand-cement bed has hardened before the pavement has been rolled, the bricks must be removed, the hardened bed discarded and the brick repaved on a fresh bed as specified.

Cement Grout Filler will consist of equal parts of Standard Portland Cement and fine, clean, sharp sand. Whether machine or hand-mixed, each batch shall consist of one sack of cement and one cubic foot of sand. The sand for the grout shall be sharp and thoroughly clean, and be composed of grains of such size that 75% will fail to pass the No. 30 sieve, and it shall be tested with regard to the strength of the mortar made with it.

If the grout is hand-mixed the work shall be as follows: One sack of cement with an equal amount of sand shall be thoroughly mixed together dry in a box preferably about four (4) feet eight (8) inches long, thirty (30) inches wide, and fourteen (14) inches deep, resting on legs of different lengths, so that the mixture will rapidly flow to the lower corner of the box, the bottom of which shall be about three (3) inches above the pavement. One box shall be used for each fourteen (14) feet in width of roadway, and at least two (2) boxes must be used in all cases.

After the cement and sand have been thoroughly mixed until the mass assumes a uniform color, enough clean water shall be added to obtain a grout that will give the best results. From the time the water is applied until the last drop is removed, and floated into the joints of the pavement the mixture must be kept in constant motion. Before the grout is applied the brick shall be thoroughly wetted by being gently sprayed.

The grout shall be removed from the box with scoop shovels and applied to the brick, in front of the sweepers, who shall rapidly sweep it lengthwise of the brick into the unfilled joints, until the joints are filled to within one-half (1/2) inch of the top of the brick. After the grout has had a chance to settle into the joints and before the initial set develops, the balance of every joint shall be filled with a thicker grout, and, if necessary, refilled until the joints remain full to the top.

After this application has had time to settle and before the initial set takes place, the pavement shall be finished to a smooth surface with a squeegee having a rubber or leather edge, which shall be worked over the brick at an angle with the courses of the brick.

In the case of Hillside brick, the grooves must be swept clean of grout before same has become hard.

The cement grout may be mixed in a suitable grout-mixing machine, satisfactory to the Engineer. The machine must be of the batch type and of one-sack capacity. Each batch must remain in the mixer a full minute and the amount of water must be kept uniform for each batch. The grouting operations must be carried out substantially as specified above.

When completed and the cement has received its initial set, the pavement shall be covered with a one-half (1/2) inch layer of sand, and shall be kept moistened for at least five (5) days. No travel shall be permitted on the pavement for a period of at least ten (10) days after grouting, or longer as directed. Ample barricades and watchmen shall be provided by the Contractor for the proper protection of the grouting.

Pitch-Mastic Filler consists of coal tar pitch and sand, and shall be made and applied as follows:

The pitch shall be of 115 degrees F., melting point, similar to that specified for granite pavement, and clean, fine sand, such as used for asphalt pavement. The temperature of the sand and pitch will be determined by the Engineer, but the sand will be heated to a temperature of not less than 400 degrees F., and the pitch to a temperature of not less than 350 degrees F.; they will be mixed in small batches in the proportion of one part sand to one part pitch. The apparatus and methods used for the mixing must be such as will meet the approval of the Engineer.

The mastic shall be applied to the pavement immediately after mixing, and shall be quickly squeegeed into the joints until same are flush full.

It is essential that the joints be filled flush full and with a slight surplus on top and the surface shall be gone over the second and third time if necessary to produce this result.

A top dressing one-quarter (1/4) inch in depth of coarse torpedo sand will be applied immediately after the filler is applied. The torpedo sand shall consist entirely of grains between one-sixteenth (1/16) and three-sixteenth (3/16) inch in size, shall be perfectly dry when applied and shall be spread uniformly over the entire surface. The top dressing shall then be rolled with some weight roller as previously mentioned, and the street shall be immediately thrown open to traffic