Modular ratio: In the elastic theory for the reinforced concrete structure, concrete and reinforcing steel are converted into one material. This is done by using the modular ratio 'm'. It is the ratio of modulus of elasticity of steel and concrete.
What is the importance of modular ratio?
Modular ratio is the ratio of Modulus of Elasticity of Steel to Modulus of Elasticity of Concrete, Modular ration significance is to finding losses in prestress. because of the influence of creep. Reinforced concrete is made up of two material,ie,concrete and steel.
Why modular ratio is used in working stress method?
The WSM method takes into consideration the strain compatibility. This means the strain in steel is assumed to be equal to that of concrete. This will make the stress in steel to have a constant relationship with the concrete adjoining by means of a constant factor. This factor is called as Modular Ratio.
What is modular ratio significance in design?
Modular ratio is the ratio of the modulus of elasticity of two different materials. If E1 and E2 are the Young's modulus of two materials, then the ratio E1/E2 or E2/E1 is known as modular ratio. In structures involving composite materials this modular ratio plays a significant role in the load shared by the materials.
What is the modular ratio to be used in the analysis of RC beams using working stress method if grade of concrete is M20?
Detailed Solution. This value of the modular ratio partially takes into account the long-term effects of creep. σ c b c for M20 is 7 MPa and the modular ratio comes out to be 13.
35 related questions foundWhat is the modular ratio to be used in the analysis of RC beams using working stress method?
In the working stress method, the modular ratio, m has a value of 280/(3 × permissible compressive stress).
What is modular ratio in civil engineering?
Modular ratio is basically the ratio of elasticity of two different materials, in case of RCC it is the ratio of elasticity of the steel to the elastictiy of concrete.
What is meant by modular ratio in RCC?
Modular Ratio in RCC is defined as the ratio between Modulus of Elasticity of Steel and Modulus of Elasticity of Concrete (Es/Ec). Where Es is the modulus of elasticity of steel which is 2,00,000 N/mm2. However concrete does not have a definite value of modulus of elasticity as it is not a perfectly elastic material.
What is the effect of creep on modular ratio?
Long term modulus of elasticity: The long-term modulus of elasticity is considered to take into account the effect of creep and shrinkage. where σcbc is permissible compressive stress in concrete in bending. ∴ Modular ratio increases if the creep effect is considered.
Where is working stress method used?
Working Stress Design Method is a method used for the reinforced concrete design where concrete is assumed as elastic, steel and concrete act together elastically where the relation ship between loads and stresses is linear.
How many reinforcements are in a beam?
Types of Reinforcement in Beams
Generally a beam consists of following steel reinforcements: Longitudinal reinforcement at tension and compression face. Shear reinforcements in the form of vertical stirrups and or bent up longitudinal bars.
What is modulus ratio of rock?
Modulus ratio reflects the quality of rock, and the quality of rock mass will be less than that of the intact rock. The M rj /M ri should have been less than 1.0 and may be 1/2, 1/3, 1/4 depending upon the quality of rock mass.
What is Young's modulus of concrete?
Default Young's modulus E. Here, E is Young's modulus and EC = 18.275 MPa (2,651 psi) (which is the value of Young's modulus when f ' c = 10 MPa (1,450 psi)). This value of EC is for simulations that are modeled linear to the peak (no prepeak hardening). Poisson's ratio is typically taken as being between 0.1 and 0.2.
What is the ratio of M20 concrete?
Different mixes (M) come in various mix proportions of the various ingredients of cement, sand and coarse aggregates. For instance, M20 comes in the respective ratio of 1:1:5:3.
What is sigma CBC?
Maximum permissible stress in steel =σst. Maximum stress in equivalent concrete area at the level of steel= \frac{\sigma _{st}}{m} Note: 1. The suffix cbc in σcbc stands for permissible stress in concrete in bending compression. The suffix st in σst stands for permissible stress in steel in tension.
What is the modular ratio Mcq?
Modular ratio: It is the ratio of modulus of elasticity of steel and concrete.
What is factor of safety for concrete?
Detailed Solution. As per IS 456:2000, the partial factor of safety for concrete is taken as 1.5. Higher factor of safety is required for concrete owing to uncertainty in preparation, transportation and placement in concreting.
Which grade of concrete is normally used for beams and slabs Mcq?
M20 is right one. - Used in footings of columns and raft foundation, used in beams, slabs, columns, stairs and walls of ordinary, single story and temporary buildings and used in retaining walls, pavements, floors and bedplates etc.
What is modulus of elasticity of rocks?
Intact rock elastic modulus
The static elastic modulus of an intact rock, Ei, is typically calculated as the slope of the stress–strain curve of a rock deforming under uniaxial compression (Ulusay and Hudson 2007). We calculated the static elastic modulus for our samples from the UCS and the triaxial tests.
What is RMR in geology?
The rock mass rating (RMR) is a geomechanical classification system for rocks, developed by Z. T. Bieniawski between 1972 and 1973.
What Poisson's ratio tells us?
Poisson's ratio (ν) Poisson's ratio measures the deformation in the material in a direction perpendicular to the direction of the applied force. Essentially Poisson's ratio is one measure of a rock's strength that is another critical rock property related to closure stress.
How many reinforcements are in a slab?
Minimum reinforcement in slab as per ACI code
As per ACI Code, In slab, minimum reinforcement shall be 0.18% of gross sectional area (B×D), taking B= 1m width of slab and D= overall depth including cover, then minimum reinforcement will be = 0.18/100× × 100× D = 0.18D sq.
Why do we use stirrups in beams?
The main aim of providing stirrups in beam is to hold the main reinforcement rebars together in RCC structure. They are provided at proper intervals to beam and columns for preventing them from buckling. Stirrups also protect the RCC structures from getting collapsed during earthquakes.
