Civil engineering board and affiliate programs

 PRE-STRESSED CONCRETE PART 1 Pre-stressing is a way of counteracting the effect of external loads on structure by imposing a state of stresses contrary to the load effects Pre-stressing has two parts Pre-Tensioning Usually straight or harped profiles, mostly used in the precast industry some example would be hollow core slabs, precast beams, Girder beams Post Tensioning Any type of profile, can be precast or cast in place The only basic difference between pre-tensioning and post tensioning is the state of the structural element while the stressing activities are done. In pretension the stressing is applied prior to concreting while in post tensioning the stressing is applied after the concrete is poured and hardened Further, Post Tensioning is divided in to bonded and unbonded systems; we will get in to this in later days. Pre-stressing a concrete element has two effect axial and transversal based on the tendon profile and anchorage selected. We can have...

  Design Procedure for One Way Slab Here are the steps for the Design Procedure for One Way Slab in steps.For those who do not know what are the design requirements of a slab design  There are two types of slab classification based on the direction of bending occurs in these slabs.The two classifications are one-way slab and two-way slab.The basic difference between these slabs are one-way slab bends only in one direction and two-way slab bends in two directions as shown in the below figure.  Design Procedure Steps for One Way Slab 1.Based on the stiffness requirement assume suitable depth and calculate the effective span 2.Calculate the loads acting on the slab. 3.Calculate factored moment and shear force by considering the one-meter width of the slab  For simply supported slab  Factored moment =Mu= Wu× l²/ 8 Shear Force = Vu = Wu×l / 2 4.Determine the minimum depth required to resist bending moment by equating  Mu= Mulim = k×fck×bd² b=1000mm k=0.138 For F...

shear force shear failure is sudden and brittle failure. The failure is  with diagonal cracks occuring some distance from the face of support. on any given section shear and flexure occur at the same time( except point with either shear or moment is zero). The interaction of the two stresses, if the principle of stress transformation is followed, develop tension and shear at an angle different from 0 or 90°. The diagonal tension resulting from interaction of shear and flexure is responsible for shear failure. beams without shear reinforcement fail in one of the five modes: ☑️diagonal tension ☑️shear compression ☑️shear tension ☑️web crushing and ☑️arch rib failure. The failure mode likely to occur depends on: ☑️moment to shear ratio( M/V), ☑️ type of loading(concentrated or distributed) ☑️beam cross section. concrete without shear reinforcement resists shear by the contribution of: ☑️concrete uncracked section, ☑️aggregate interlock and ☑️du...