Thursday, March 22, 2018

What are concrete cover blocks?

What are concrete cover blocks?

Cover blocks are used to maintain a specified distance between the TMT rebar and the shuttering.

A cover block is essentially a spacer that is used to lift the rebar matrix off the ground so that concrete may flow underneath the rebar.

Why we must use cover blocks?

  • When doing RCC work it is important to embed the steel in the concrete (also known as cover) so that the rebar doesn’t corrode and to provide fire protection to the rebar.
  • If we don’t provide the recommended cover the rebar will corrode with time and will ultimately result in premature failure of the structure.
  • Thus using cover blocks enhances the life of the structure significantly without adding much to the cost.

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Tuesday, March 13, 2018

Future Changes in Construction Industry

  • Construction Software and Full Integration
One of the elements that has made construction software so indispensable has to do with the fact that it allows for the real- time exchange of information between the various project agents.
This means a significant decrease of budget miscalculation and task delays.

Monday, March 12, 2018

The 10 Longest Floating Bridges in the World

Lacey V. Murrow Memorial Bridge, SeattleU.S.A, 2,020 meters, 1940. The bridge carries the eastbound lanes of Interstate 90 across Lake Washington from Seattle to Mercer Island, Wash. The world’s first floating bridge to be built using concrete pontoons, it was designed by engineer Homer Hadley, and constructed by the Puget Sound Bridge and Dredging Co., at a price tag of $9 million. While undergoing reconstruction in 1990, an 850-m-long section of the bridge sank when a storm filled one pontoon. The rebuilt bridge reopened in 1993, at a cost of $93 million

Thursday, March 01, 2018

Roads with Plastic waste

All kind of plastic waste collected from the garbage, than sorted, cleaned and shredded to manufacture flakes called as KK Poly Blend. This blend is mixed in the ratio of 8: 100 to the total weight of bitumen in hot mix plant. In hot mix plant, the material is being pumped using specially designed machinery where the blend is sprayed on aggregate at 160 degree Celsius. The plastic gets coated to aggregate and then over coated with bitumen thereby enhancing the bonding strength of aggregate and bitumen. The mix needs to be laid minimum of 100 degree Celsius while asphalting roads for better results.
Technology: The Central Road Research Institute and Center for Transport Engineering, Bangalore University has certified that the addition of 8% K K Poly Blend to bituminous concrete mix will not only increase the Marshall Stability, flow value and comprehensive strength of bitumen but also increases the values of fatigue life and indirect tensile strength by three times when compared with conventional mix. The use of this technology has enhanced the roads' durability, efficiency and performance by 2 folds to that of plastic free roads at a merger additional cost.


StaadPro Analysis methods

STAAD.Pro offers several analysis methods as noted below:
Perform Analysis - instructs STAAD to perform a linear elastic (stiffness) analysis.

P-Delta Analysis - performs a second-order elastic analysis that considers the effects of the applied loads acting on the displaced structure (P-Δ effect). This type of analysis is generally preferred by most building codes. This is an iterative analysis process. This analysis type also has options to specify the number of iterations to be performed or to place a convergence tolerance on the displacements from successive iterations. There is also an option to include the P-δ (small delta) effect, which considers the effect of applied loads acting on the deformed shape of individual members. Finally, this analysis includes an option to include the Geometric Stiffness (Kg) matrix, which modifies the member stiffnesses based on the applied loads.

Cable Analysis - performs a non-linear cable analysis on a structure that contains non-linear cable members

Direct Analysis - performs a Direct Analysis. This method accounts for the second-order effects resulting from deformation in the structure due to applied loading, imperfections, and reduced bending stiffness of members due to the presence of axial loads. This analysis is similar to a P-Delta Analysis with the Use Geometric Stiffness (Kg) and Small Delta options selected. However, this analysis calculates modifications to the stiffness matrix using the τb factors described in AISC 360-05.

Generate Floor Spectrum - used to request the calculation of floor and/or joint response spectra from time history results. This is particularly useful in the analysis of floor systems supporting vibrating equipment. This feature requires a license for the Advanced Analysis Engine.

Imperfection Analysis - considers the secondary effects of loads acting on members that have an initial curvature (camber) or an initial drift This analysis is used on structures that have members with an Imperfection specification applied to them.