Slab Design

REINFORCEMENT DETAILING OF RCC SLAB OPENINGS (CUTOUTS)

Many times openings (cutouts) are required to be provided in reinforced concrete slab in buildings to provide way for lifts, or cables, ducts or other instrument to pass through one floor to other floors, mainly in the case of industrial buildings. But in that case, special care need to be taken while detailing of reinforcement(…)

VOIDED SLAB – BUBBLE DECK TECHNOLOGY

In the 1950s, hollow-core slab were invented. The voided or hollow core system was created to reduce the weight of the concrete from the system. This concept removes and replaces concrete from center of the slab, where it is less useful with lighter material in order to decreases the dead weight of concrete floor. However,(…)

RCC SLAB DESIGN AND DETAILING GUIDE

RCC Slab Design Guidelines: a) Effective span of slab: Effective span of slab shall be lesser of the two 1.  L = clear span + d (effective depth ) 2.  L = Center to center distance between the support b) Depth of slab: The depth of slab depends on bending moment  and deflection  criterion.  the(…)

DESIGN OF SLAB – BASICS

DESIGN OF SLAB Slabs are generally designed on the assumption that they consists of a number of beams of breadth ‘one meter’. Effective Span The effective span of a simply supported slab shall be taken as the lesser of the following: Distance between the centers of bearings, Clear span plus effective depth Thickness of Slab(…)

YIELD LINE THEORY FOR SLAB DESIGN

In the case of two-way slab systems, which are statically indeterminate, detailed inelastic analysis (yield line analysis) is conducted. The moment coefficients given in the Code IS 456:200(Table 26) for two-way rectangular slabs with various possible edge conditions are based on Yield Line Analysis. ‘Yield line analysis’ is the equivalent for a two-dimensional flexural member(…)

Precast Concrete Methods

Precast concrete means a concrete member that is cast and cured at a location other than its final designated location. The use of reinforced concrete is a relatively recent invention, usually dated to 1848 when jean-Louis Lambot became the first to use it. Joseph Monier, a French gardener, patented a design for reinforced garden tubs(…)

Punching shear resistance of high-strength concrete slabs

Concrete with strengths above 50 MPa is currently used due to an increasing requirement for higher strengths and improved long-term properties. HSC is being utilised in many projects. High-strength concrete members exhibit, in some instances, different failure mechanisms and simply extrapolating models and equations meant for normal strength to high-strength concrete may lead to unsafe(…)

Detailing of Transverse Reinforcement

The detailing of reinforcement is as important as the analysis and design of any RCC members. Specially it is true in the design of structures against the SEISMIC forces. The most and very important aspect of detailing is well documented in the text book on “SEISMIC DESIGN OF REINFORCED CONCRETE AND MASONRY BUILDINGS by T.Paulay(…)

SLABJACKING

The purpose of slab jacking is to raise a slab in place permanently, prevent impact loading, correct faulty drainage, and prevent pumping at transverse joints by injection of a grout under the slab. The grout fills voids under the slab, thereby restoring uniform support when necessary.

RCC SLAB CASTING – WORK PROCEDURE

The construction joint shall be pre decided and fixed prior to start of the concreting. It is planned to have two construction joints for main building as decided. In case of major break down of the Batching plant, the additional Construction joint may be left. The location of the construction joint shall be at the one-third span. Construction joint shall be straight and have profile of ‘L’shape so that successive layer of concrete shall be perfectly bonded with previous laid layer.