STRUCTURAL DESIGN 2 INTRODUCTION.pdf

02/09/2024 Engr. Rubylyn Marudo-Tagabuan, RCE What is CONCRETE? It is a mixture of sand, gravel, crushed rock or other aggregates held together in a rocklike mass with a paste of cement and water. It has a high compressive s...

02/09/2024 Engr. Rubylyn Marudo-Tagabuan, RCE What is CONCRETE? It is a mixture of sand, gravel, crushed rock or other aggregates held together in a rocklike mass with a paste of cement and water. It has a high compressive strength and very low tensile stress. Click to edit Master subtitle style REINFORCED CONCRETE is a combination of concrete and steel wherein the steel reinforcement provides the tensile strength lacking in the concrete 1  02/09/2024 AGGREGATES Aggregates used in concrete may be fine aggregates (usually sand) and coarse aggregates (usually gravel or crushed stone). Fine aggregates are those that passes through a No. 4 sieve (about 6 mm in size). Materials retained are coarse aggregates. WATER Water used in mixing concrete shall be clean and free from injurious amounts of oils, acids, alkalis, salts, organic materials, or other substances that may be deleterious Click to edit to concrete Master subtitle style or reinforcement. Mixing water for prestressed concrete or for concrete that will contain aluminum embedment, shall not contain deleterious amounts of chloride ion. Non-potable (non-drinkable) water shall not be used in concrete. ADVANTAGES 1. It has considerable compressive strength per unit cost compared with most other materials 2. Reinforced concrete has great resistance to the actions of fire and water and, in fact, is the best structural material available for situations where water is present. During fires of average intensity, members with a satisfactory cover of concrete over the reinforcing bars Click suffertoonly editsurface Master subtitle damage style without failure. 3. Reinforced concrete structures are very rigid. 4. It is a low-maintenance material. 5. As compared with other materials, it has a very long service life. 2  02/09/2024 ADVANTAGES 5. It is usually the only economical material available for footings, floor slabs, basement walls, piers and similar applications. 6. A special feature of concrete is its ability to be cast into an extraordinary variety of shapes from simple slabs, beams, and columns to great arches and shell. Click to edit Master subtitle style 7. Inexpensive local materials. 8. It requires lower labor cost, compare to other material such as structural steel. DISADVANTAGES 1. Concrete has a very low tensile strength, requiring the use of tensile reinforcement. 2. Forms are required to hold concrete (formworks are expensive) Click to edit Master subtitle style 3. Higher / heavy self weight. 4. The properties of concrete can vary widely because of variations in its proportioning and mixing, and curing is not carefully controlled. 3  02/09/2024 ACI 318 – 14 (LATEST 318-19) CODE REQUIREMENT FOR STRUCTURAL CONCRETE  Most important code in the united states for Reinforced Concrete design  Set of recommendations or statement of current good practice in Reinforced Concrete Design Click to edit Master subtitle style AMERICAN CONCRETE INSTITUTE  Author of ACI 318 -14  Non-profit technical society & standards developing organization NSCP 2015 National Structural Code of the Philippines  Address the design & installation of structural system in the Philippines Association of Structural Engineers of the Phil. (ASEP)  Author of NSCP 2015  Organization of structural designers/engineers in the Philippines Click to edit Master subtitle style 4  02/09/2024 COMPRESSIVE STRENGTH OF CONCRETE, f’c ENGLISH UNITS S.I. UNITS 3000 psi – 4000 psi 20.68 Mpa – 27.58 Mpa (ordinary applications) 5000 psi – 6000 psi to edit Master subtitle style Click 34.47 Mpa – 41.37 Mpa (for prestressed construction)