Expansion Joints, Embedded Items and Construction Joints

Expansion Joints, Embedded Items and Construction Joints

Expansion joints

https://daecivilinfo.blogspot.com/2020/08/expansion-joints-embedded-items-and.html

Expansion joints shall be provided wherever located on the drawing or as directed by the engineer. In no case  shell the reinforcement corner protection angles or other embedded items be run continuously or through an expansion joints. All expansion joints shall be carefully placed so as not to be  displaced during concreting. The method of placing  the expansions joint shall be strictly according with the drawing . All the material for the use in expansion joint shall have prior approval of engineer before placing order for supply and the place where expansion joints should be places is mark by using the instrument or machine by surveyor.

Embedded Items

https://daecivilinfo.blogspot.com/2020/08/expansion-joints-embedded-items-and.html

Embedded items are any items for ducts, plates, instance pipes, sleeves or conduits placed in concrete. The material design and location of water stops in in joint shall be as indicated in the contract document. Each piece of pre molded water shall be of maximum practicable length in order that the number of end joints will be held to a minimum. Joint at intersection and ends of pieces shall be made in the manner most appropriate to the material being used. Joint shall develop effective water tightness fully equal to that of the contentious water stop material shall permanently develop not less than 50 percent of the mechanical strength of the parent section shall permanently retain their flexibility. Electric conduits and other pipes which are planned to be embedded shall not with their fittings, displace more than four percent the area of the cross section of a column on which stress is calculated or which is required for fire protection. Sleeves, conduits or other pipes passing through walls, floor and the beams shall be if such size or in location as not to impair unduly the strength of the construction such sleeves, conduits or pipe may be considered as replacing structurally they are not exposed to rusting or other deterioration are of un  coated or galvanized iron or steel not thinner than standard steel pipes have a nominal inside diameter not over  50 mm and are spaced not less than three  diameters on centers, Expect when plans of conduits and pipes are approved by the engineer embedded pipes and conduits other than those merely passing through shall not longer than outside diameter than one third the thickness of the slab, wall ,beams in which they are embedded nor construction.

                                     All sleeves, inserts, anchors and embedded  items required for adjoining work or for it's support shall be places prior than concreting.All contractor  whose work is related to the concrete or must be supported by it shall be given ample notice and opportunity  to introduce and furnish embedded items before the concrete is placed.Expansion joint  material water stopper and other embedded items should be positioned accurately and support against displacement. Voids in sleeves, inserts, and anchor slots shall be filled  temporarily with readily remove able   material to prevent the entry of concrete in voids.

Construction joint

Construction shall be carried out continuously up to construction joints the position and arrangement. Joint not shown on the drawing shall be so made and locate as to least impair the strength of the structure and shall need prior. In general they shall be locate near  the middle span of slab and beams unless a secondary beam intersect the main beam at the point in which case the joint in main beam shall be offset a distance equal to the twice of the width of the secondary beam. 

                  Joint in the wall and column shall at the top of footing or the floor slab. Beams, brackets, columns, capitals,, haunches and drop panels shall be placed at the same time as slabs. Joint shall be perpendicular to the main reinforcement.All reinforcing steel shall be continued across joint. Key and inclined dowels shall be provided by the engineer. Longitudinal keys at least 40 mm deep shall be provided in all joints in wall and between walls and slab or footings.When the work has to be resumed on a surface which has hardened such surface shall be roughened in an approved manner which will expose the aggregate uniformly and will not leave laitance, loosened particles of aggregate or damage concrete at the surface.
                  The harden concretes of joint in exposed work, joint in the middle of beam and joints in work designed and when thoroughly covered with coat of cement grout. 
                 Where the concrete has not fully hardened all laitance shall be removed by scrubbing the wet surface with wire or bristle, and brushed care being taken to avoid disgorgement of particles of aggregate.