Reinforcing metal shall be placed between base and wearing course and shall not be less than two (2) inches from the finished surface of the pavement and otherwise shall be placed as shown on the drawings. The reinforcing metal shall extend to within two (2) inches of all joints, but shall not cross them. Adjacent

4 widths of fabric shall be lapped not less than four (4) inches when the lap is made perpendicular to the center line of the pavement and not less than one (1) foot when the lap is made parallel to the center line of the pavement.

Expansion Joints. - Longitudinal expansion joints will be provided along each curb if the pavement is laid with such. These expansion joints will be formed in the same manner and of same width as provided for "Brick Pavement," except that the joints must extend entirely through the concrete.

At intervals of thirty (30) feet there shall be constructed transverse expansion joints. Such joints shall be straight and perpendicular to the center line of the pavement, shall extend through the full depth of the concrete, and corresponding points on the two edges of the joints shall be at the same elevation.

Expansion joints shall be formed by inserting during construction and leaving in place a total thickness of three-eights (3/8) of an inch of tarred paper or felt treated with tar or asphalt, previously prepared in the form of a built-up board. They shall project not less than 1/2 inch above the finished surface and before the pavement is opened to traffic the joint fillers shall be cut off to a height of 1/4 inch above the surface of the pavement.

Placing Concrete. - Immediately prior to placing the concrete, the sub-grade shall be brought to an even surface. The surface of the sub-grade shall be thoroughly wet but shall show no pools of water when the concrete is placed.

After mixing, the concrete shall be deposited rapidly upon the sub-grade, to the required depth and for the entire width of the pavement in successive batches and in a continuous operation without the use of intermediate forms or bulkheads between expansion joints. If the concrete is placed in two courses, as when reinforcement is used, any dirt, sand or dust which collects on the base course shall be removed before the top course is placed. The concrete above the reinforcement shall be placed immediately after mixing and in no case shall more than forty-five (45) minutes elapse between the time that the concrete below the reinforcement has been mixed and the concrete above the reinforcement is placed.

In a case of breakdown, concrete shall be mixed by hand to complete the section or an intermediate transverse joint placed as hereinbefore specified at the point of stopping work. Any concrete in excess of that needed to complete a section at the stopping of work shall not be used in the work.

Finishing. - The surface of the concrete shall be struck off for the entire width of the pavement, and from back to back of integral curbs when used, by means of a template or strikeboard. Any holes left by removing any material or device used in constructing the joint shall be filled immediately with concrete from the latest batch deposited on the sub-grade. Concrete adjoining metal protection plates at transverse joints shall be dense in character and shall be given a smooth finish with a steel trowel for a distance of six (6) inches on each side of the joints. The concrete adjacent to unprotected joints shall be finished with a wood float, which is divided through the center and which will permit finishing on both sides of the filler at the same time. The concrete for a distance of eighteen (18) inches out from the curb line shall be finished with a steel trowel, if ordered by the Engineer.

After being brought to the established grade with the template or strike-board, the concrete shall be finished from a suitable bridge, no part of which shall come in contact with the concrete. If approved by the Engineer, the Contractor may use a mechanical striking and finishing machine. The concrete shall be finished with a wood float in a manner to thoroughly compact it and produce a surface free from depressions or inequalities of any kind. The finished surface of the pavement shall not vary more than one-quarter (1/4) inch from the specified contour.

With the Engineer's permission, the finishing may be done with suitable belts instead of the wood float.

Curing and Protection. - Except as hereinafter specified, the surface of the pavement shall be sprayed with water as soon as the concrete is sufficiently hardened to prevent pitting, and shall be kept wet until an earth or other approved covering is placed. As soon as it can be done without damaging the concrete, the surface of the pavement shall be covered with not less than two (2) inches of earth or other material approved by the Engineer, which cover shall be kept wet for at least ten (10) days. When deemed necessary or advisable by the Engineer, freshly laid concrete shall be protected by canvas until such covering can be placed.

Under the most favorable conditions for hardening in hot weather, the pavement shall be closed to traffic for at least fourteen (14) days, and in cool weather for an additional time, to be determined by the Engineer.

When the average temperature is below fifty (50) degrees Fahrenheit, sprinkling and covering of the pavement may be omitted at the discretion of the Engineer.

The Contractor shall erect and maintain suitable barriers to protect the concrete from traffic and any part of the pavement damaged from traffic or other causes, occuring prior to its official acceptance, shall be repaired or replaced by the Contractor at his expense, in a manner satisfactory to the Engineer. Before the pavement is thrown open to traffic the covering shall be removed and disposed of as directed by the Engineer.

Cold Weather Work. - Concrete shall not be mixed nor deposited when the temperature is below freezing.

If, at any time during the progress of the work, the temperature is, or in the opinion of the Engineer will within twenty-four (24) hours drop to 35 degrees Fahrenheit, the water and aggregate shall be heated, and precautions taken to protect the work from freezing for at least ten (10) days. In no case shall concrete be deposited upon a frozen sub-grade.

Blocking. - Where the finished pavement is to be grooved, the following shall be observed: The concrete shall be struck off and approximately finished at depth of from one-half (1/2) inch to one and one-quarter (1 1/4) inches below the proposed finished grade, and on this surface shall be placed a top course of mortar composed of one (1) part cement to one and one-half (1 1/2) parts of sand. The mortar shall be placed as quickly as possible after the placing of the concrete, so as to bond thoroughly with same and shall be finished by template and float or belt as specified above. Before the mortar surface has taken its initial set, it shall be neatly and carefully blocked into rectangles six (6) inches by twelve (12) inches by grooves from three-eights (3/8) to three-quarters (3/4) inch in width and depth.

The depth of the mortar top depends on the size of the grooves which will be shown on the drawing or described under "Special Requirements." In all cases the depth specified for the completed pavement shall include the mortar top.

Payment. - The price bid per square yard will be for the entire work complete as specified above, and shall include all work necessary under the item of "Grading" when no special price is bid for such work.

When integral concrete curb is used the concrete pavement will be paid for by the square yard surface measure, measuring from back to back of curb, following the contour of the curb and gutter. The shaping and finishing of the integral curb will be paid for under Item 45.