Ee PRODUCTS PROJECTS BUSINESS HOWTO CONCRETE SURFACES RESOURCE CENTER NT aT ap TER ald a Howto Repl a Pedra 6 2020, icRI GUIDE TO HOW TO REPAIR CONCRETE STRUCTURES New documents raise the performance level of repalr and protection systems. INTHE KNOW THREE MYTHS ABOUT CONTRAG’ IN RESIDENTIAL SLABS [Not installing joints opens the potential litigation in addtior HOW LONG CAN A READY-MIX T Wie were all et to start when Jabs field tech stopped the po ei ld iB) ess) iseused fr the repair of deteriorated concrete surfaces using cement-based repair materials and to highlight the applications {for which each method i considered tobe mest suitable” Combined these documents provide guidance that elevates repair 1 the same level asthe design and construction of new concrete structure. The industry recognized that oo many concrete repairs were falling much too cen. The advice in these new resources provides a way to consistently produce durable concrete repairs. ICRI Repair Guide ‘The ICRI guide starts with this statement “Achieving success in concrete repair begins withthe recognition that each repair situation is defned by a unique combination of circumstances including type and extent of deterioration, structure ‘ype, expesure, working environment, personnel, schedule and others! That means that esch repair project should have a fexibie approach, while still adhering te Une bases, Lalso means that mock-ups are often needed to Vey thatthe proposed ‘approach wil satisfy the project requirements” (one basic requirement fo any epai project s surface preparation, “The quality of surface preparation is prcbably thesingle ‘est important factor that contributes to the success of a repair. Substrate shouldbe sound, roughened, clean, and saturated surface dry! The guide goes onto describe the factors that influence suface preparation repair material robe used desired concrete surface profile (CSP), methods and equipment tobe used, possible presence of contaminants the substrate moisture condition, the desired cleanliness of reinforcing steel, and the presence of cracks and joints. BATCH SIZE ‘The volume of repair material application isinfuenta inthe selection of mixer type and aplication method, Selection of Repair Methods ‘The essential content in 1OR! 2201 isa systematic approach to selecting the materials and methods for a repair. Here's how roster 1 Consider the repair material properties most necessary 19 estore the integrity ofthe erginal design and to remsin durable in the service environment. 2.Consider the methods of repair material placement that can be used to sffecively and efficiently place the repair material conto the prepared concrete Tis typically includes consideration of site constraints and total quantities af reps. 23. Selecta repair material thet provides the needed material properties and that can be placed by the most appropriate application method, JoRI encourages the repair contract 1 place the durability ofthe repair above ease of application and, when in doubt to Tse‘quantities of material and ten to vequte more automated methods of application! The thre repalr application methods to consider are unformed hand-applied. formed applications, ana pneumatically applied (shoteret). ‘The guidance for each of thece three metheds is divided into lve categories» A general description, + The best applications fer each method +The material requirements. +The advantages + Cautions ane limitations. Unformed Hand-Applied Method: “This application methed is typical intended for shallow, non-structural, resurfacing of deteriorated vertical and overhead concrete eubstales where sel reinforcement is not visible alter prepating lhe repait area” This method is oly intended for non-structural repairs, and its ideal for small-scale reais, Formed Application Methods: There are four ofthese to consider, + Dry Packing Suitable for repair of relatively low-volume cavities witha high degree of confinement and open-sided + Form and Pour/Patial- and Full-Depth Cast Repairs "Use fr clurnns, walls, beams, and slabs with a repair ‘thickness/depth of approximately 2 inches or mare! + Form and Pump"Suitable for overhead and vertical applications, including where reinforcing ste! is exposed” + Preplaced Aggregate ‘Suitable for vertical and ovethead applications where extremely low shrinkage of repair material is required? Pheumatially Applied Methods: There are three shoterete methods ta consider for reales + Diy-Mix Shotorete Best suited fr lage vertical and overhead areas or curved surfaces with small-lameter bars and ‘minimal congestion of reinforcement” Dry-mix has the advantage over wel-mixof allowing thicker buildup on overhead surfaces is also easier to start and stop since the materials remain dry until they reach the nozzle. + Wet-Mix Shoterete Wet-mix s suitable for the same applications as dry-mixbut has the advantages of greater placement sates and less teboursd, + Low Pressure Spray: “Typically used for vertical and overhead repairs! Tais method produces less rebound than traditional ‘wets or dry-mix shotorete and since the noznle can be closer tothe repr surface t can be used in signer spaces, BATCH SIZE Bulk Batching Packaged Site Mixed Bulk Site Mixed Tsea consideration :n any construction projec, including ential hazards include those fo nt (heat falls), repair materials (cement burns}, and equipment us vole envizonan safe construction site only when ere is @ culture of safety that inch ‘awareness and recognition, and accountability? esshuland ‘very repr projact has its own unique challenges Felloting these guidelines doesn't necessarily assure ast durable repair but it does provide a system for making Jon the many years of experience from the authors. cling Application Methods far the Re members Copies ofthe Guide fs avilable ateror5 1 inthe latest version of the American Cone he improvements and upds Code Requirements for Assessment, Repair and Rehabilitation of Existing Concrete to read that article, ABOUT THE AUTHOR Palmer ian omer ar ot aly Woo Conese otra Cre, ene land pri res of ae ‘ust, ac Surtas, Th Conte Pb Wor at Mam Cstnco Pre wkd re Aneran Cana stint fr 10 oars as ageing ear addr uc rans an wast msn desert Anta Suet of Cnr Contre ASC] eo The any Say. Hea en er nce of Can Catt fr 16 esa Flo the aia Cece tote a cals presale in igs andl, Hees a as Carat. Fle an iter inane ene Koyo Sabet [MORE FROM CONCRETE CONSTRUCTION = ‘overcast. ‘CHOOSING THE BEsT WoRKERS* ‘COMPENSATION INSURANCE FOR YOUR BUSINESS ‘Factors fo Conse When Slesting Workers Comp Farner ise