Awarded as the best online publication by CIDC
There are many tests which are conducted to check the quality of concrete. These tests are basically divided into two categories
1. Various Lab Test On Fresh Concrete.
Under these, we have the following tests
a) Slump Test – Workability
b) Compacting Factor
c) Vee- Bee Test
There are many tests which are conducted to check the quality of aggregates. Aggregates are very important component of concrete, so the quality really matters when it comes to aggregates.
Various test which are done on aggregates are listed below.
Checking of materials is an essential part of civil engineering as the life of structure is dependent on the quality of material used.Following are the tests to be conducted to judge the quality of cement.
1. REQUIREMENTS
a) Specified minimum strength = 20 N/Sq mm
b) Durability requirements
i) Exposure Moderate
ii) Minimum Cement Content = 300 Kgs/cum
c) Cement
(Refer Table No. 5 of IS:456-2000)
i) Make Chetak (Birla)
ii) Type OPC
iii) Grade 43
It was an unfortunate morning of 7th November 1940 when winds having speed of 42 miles per hour suddenly twisted the Tacoma Narrows Bridge and lead to its collapse. This accident though didn’t look any lives but it surely made the civil engineers to think new ways to combat bridge collapses.
Some of the important statistics of this bridge are –
It is located in Tacoma, Washington, USA and was completed in 1940. This was a suspension type of bridge with length of 7,392 feet and was built at the cost of $6.4million.It had the longest span of 2800 feet.
CONCRETE MIX DESIGN (GRADE M60)
(a) DESIGN STIPULATION:-
Target strength = 60Mpa
Max size of aggregate used = 12.5 mm
Specific gravity of cement = 3.15
Specific gravity of fine aggregate (F.A) = 2.6
Specific gravity of Coarse aggregate (C.A) = 2.64
Dry Rodded Bulk Density of fine aggregate = 1726 Kg/m3
Dry Rodded Bulk Density of coarse aggregate = 1638 Kg/m3
Read More
Earthquake Details
Instant Concrete road repair solution
By Mr. Mangesh Dhamele
Dy. Manager. Choksey Structural Engineering
INTRODUCTION
The Durability of road structures depends on the quality of its maintenance & minor renovations. Maintenance keeps the roadway safe, provides good driving conditions & prolongs the life of the pavement, thus protecting the road investment.
Currently in India more than 2000 km of concrete road is in the operation since last few years. Most of the projects completed by NHAI, MSRDC and other state government authorities. Though the quality & procedural aspects, specifications / guidelines clearly mentions in IRC, MoRTH, but still we observes that various minor cracks, potholes and joints edge spalling in the PQC due to various factors which requires maintenance. Maintenance includes the prompt sealing of cracks & filling of potholes to prevent water entering through the surface.
Millau Viaduct France (In French le Viaduc de Millau) is one of the most awesome civil engineering project. It is a large cable-stayed road-bridge that spans the valley of the River Tarn near Millau in France. It was designed by structural engineer Michel Virlogeux and architect Norman Foster.One of the summit of this bridge is at a height of 343 meters)1125 ft) which makes it is the tallest vehicular bridge in the world.
The Millau Viaduct consists of an eight-span steel roadway supported by seven concrete pylons. The roadway weighs 36,000 tons and is 2,460 m (8,100 ft) long, measuring 32 m (100 ft) wide by 4.2 m (14 ft) deep, making it the world’s longest cable-stayed deck. The six central spans each measure 342 m (1,120 ft) with the two outer spans measuring 204 m (670 ft). The roadway has a slope of 3% descending from south to north, and curves in a plane section with a 20 km (12 mi) radius to give drivers better visibility. It carries two lanes of traffic and one safety lane in each direction.
The mix design for M35 Grade Of Concrete for pile foundations provided here is for reference purpose only. Actual site conditions vary and thus this should be adjusted as per the location and other factors.
Grade of Concrete : M35
Characteristic Strength (Fck) : 35 Mpa
Standard Deviation : 1.91 Mpa*
Target Mean Strength : T.M.S.= Fck +1.65 x S.D.
(from I.S 456-2000) = 35+ 1.65×1.91
= 38.15 Mpa
Read More
