2017-10-19_REVISION - M2000041 - Laserfiche WebLink

Home Browse Search

All improperly cured or otherwise defective mortar shall be removed and replaced by the Contractor at his expense. PART 3-EXECUTION 3.01 FORMS The concrete forms shall be constructed to the lines and dimensions as shown on the detailed drawings and shall be of acceptable material and adequately braced and tied to support all of the loads and pressures of the wet concrete without distortion or leaks,and which will produce a smooth,even surface. The form facing material shall produce a smooth,hard,uniform texture on the concrete. It may be plywood,tempered concrete-form-grade hardboard,metal,plastic,paper,or other approved material capable of producing the desired finish. The arrangement of the facing material shall be orderly and symmetrical,with the number of seams kept to the practical minimum. It shall be supported by studs or other backing capable of preventing excessive deflection. Material with raised grain,torn surfaces,worn edges,patches,dents,or other defects which will impair the texture of the concrete shall not be used. Tie holes and defects shall be patched. All fins shall be completely removed. All exposed concrete corners shall be chamfered 3/4". A water tight form tie with a neoprene seal shall be used on all walls or slabs that form a water holding space. Ties in these walls or slabs shall remain permanently in the concrete. Drawings showing the general design and dimensions for forms for structures need not be submitted to the Engineer for acceptance unless the Engineer so requests such submittal. Design and construction shall be in accordance with"Recommended Practice for Concrete Formwork"(ACI 347),and"Formwork"(ACI 301,Chapter 4). Before concrete is placed,the surface of the forms shall be oiled with a commercial form oil that will effectively prevent sticking of the concrete to the forms and will not stain the concrete. All bond breaking materials or processes shall be used only after acceptance by the Engineer. Care shall be taken in applying form oil to avoid contact with reinforcement steel. Embedded material which becomes coated with form oil shall be thoroughly cleaned or replaced at the expense of the Contractor. Supporting forms and shores shall not be removed from beams,floors,and walls until these structural units are strong enough to support their own weight and any approved superimposed load which at no time shall exceed the design live load. When the forms are stripped,there shall be no excessive deflection or distortion and no evidence of damage to the concrete,due either to removal of support or the stripping operation. Removal time of forms,shall be determined by the Engineer. 3.02 PLACEMENT Prior to placing the concrete,the Contractor shall remove all trash,pieces of wood,standing water,or other debris,and shall dampen areas on which concrete is to be placed. Placement shall conform to ACI 301,Chapter 8"Placing,"ACI 306"Recommended Practice for Cold Weather Concreting,"and ACI 305"Recommended Practice for Hot Weather Concreting." No concrete shall be placed until all formwork,reinforcement,installation of parts to be embedded,bracing of forms, and preparation of surfaces involved in the placing have been approved by the Engineer. No concrete shall be placed in water,except with the written permission of the Engineer;the method of depositing the concrete shall be subject to his approval. All surfaces of forms and embedded materials that have become encrusted with dried mortar or grout from concrete previously placed shall be cleaned of all such mortar or grout before the surrounding or adjacent concrete is placed. Immediately before placing concrete,all surfaces upon or against which the concrete is to be placed shall be free from standing water,mud,debris, or loose materials. The surfaces of absorptive materials against or upon which concrete is placed shall be moistened thoroughly so that moisture will not be drawn from the freshly placed concrete. The concrete 9/17 Section 03310-Page 5 of 8