Construction Joints. All contraction joints shall be straight, truly vertical or level, as the cast may be, of the profile shown and formed in the exact positions shown on drawings or if not shown on the drawings, with prior approval of the Engineer. Vertical joints shall be formed against adequately secured rigid stop boards having splayed fillets, designed to pass the continuous steel reinforcement without temporary bending or displacement. The rate and method of placing concrete and the arrangement of constructions joints shall be placed in a continuous operation. Joints in reinforced slabs, joists and beams, shall be perpendicular to the axis or surface of the member jointed and at the center of the span. If an intersecting member occurs at that point, the joint shall be located at a point of minimum shear. Construction joints in columns shall be as shown on the drawings. Whenever it becomes necessary to stop work, such stops shall be located at center of slabs and of beams or as directed by the Engineer. An adequate and acceptable key for succeeding work shall be formed by using stop boards which shall be constructed tightly to prevent any grout leak. As early as possible boards shall be removed and the surface thoroughly hacked and brushed to remove all laitance. Any leakage past stop boards shall be hacked off as soon as the concrete has set. The surface shall be left clean and dry. Immediately prior to further concreting the joint face shall be soaked with water and covered with sand cement mortar of proportions identical to that in the concrete to be placed, punned into the body of the set concrete. For exposed finishes, care shall be exercised to preserve an unbroken line at the exposed edge of the joint. In no circumstances shall the concrete be allowed to finish at a break running down a rough slope. Such cases, if found, will be treated as contrary to the specification and the Contractor will be required to cut out the member and re- cast. In the case of horizontal joints, any excess water and laitance shall be removed from the surface after the concrete is deposited and before it has set. Before casting slabs the haunching or seating for the slab shall be thoroughly hacked, sourced and washed and covered with at least 5 mm of mortar immediately before the slab is cast. Any necessary construction joints in foundations shall be stepped and lapped 600 mm. Joint faces shall be prepared and treated as described, above Specification Concrete Work
Construction Joints. Locate joints not shown or specified so as to least impair strength and appearance of the work. Place concrete at such a rate so surfaces of concrete which have not been carried to joint levels will not have attained initial set before additional concrete is placed thereon.
Construction Joints. Definition: Concrete surfaces, upon or against which concrete is to be placed and to which new concrete is to adhere, that have become so rigid that the new concrete cannot be incorporated integrally with that previously placed, are defined as construction joints.
Construction Joints a. A construction joint is defined as a joint in the concrete introduced for convenience in construction at which special measures are taken to achieve subsequent continuity without provision for further relative movement.
Construction Joints. They shall be either keyed or dowelled, with or without angle iron. However, chuted concrete allows the concreting of large surfaces without needing to form construction joints.
Construction Joints. Minimize the number of longitudinal and transverse construction joints. Thoroughly clean both types of joints by blast cleaning. Coat the hardened sides of the joints with an approved bonding agent before fresh concrete is placed. When necessary, form longitudinal construction joints vertical by use of a header secured to the deck. After removal of the longitudinal header and transition, saw the overlay 3 in. (75 mm) or more inside the construction joints and the overlay outside the saw cut removed before the adjacent overlay is placed. The volume of the overlay removed is not included in the volume measured for payment.
Construction Joints. In accordance with the requirements of Section 202.08 of the DPW Standard Specifications.
Construction Joints. Install so strength and appearance of concrete are not impaired, at locations indicated or approved by the Engineer.
Construction Joints. Construction joints shall be permitted only at the positions pre- determined on the Drawings or as instructed on the Site by the Engineer. In general they shall be perpendicular to the lines of principal stress and shall be located at points of minimum shear, viz., vertically at, or near, mid-spans of slabs, ribs and beams. Suspended concrete slabs are generally to be cast using alternate bay construction in bays not exceeding 20 metres in length. No two adjacent bays are to be cast within a minimum period of 48 hours of each other. The joints between adjacent bays are to be in positions agreed with the Engineer. Under no circumstances shall concrete be allowed to tail off, but it shall be deposited against stopping-off boards. Before placing new concrete against concrete already hardened, the face of the old concrete shall be thoroughly hacked, roughened and cleaned, and laitance and loose material removed therefrom, and immediately before placing the new concrete the surface shall be saturated with water and covered with a coat of mortar at least 25 mm in thickness composed of cement and fine aggregate in the proportions used in the concrete.
Construction Joints. A. Transverse construction joints shall be placed whenever placing of concrete is suspended for more than 30 minutes.
