This site uses cookies to improve your experience. To help us insure we adhere to various privacy regulations, please select your country/region of residence. If you do not select a country, we will assume you are from the United States. Select your Cookie Settings or view our Privacy Policy and Terms of Use.
Cookie Settings
Cookies and similar technologies are used on this website for proper function of the website, for tracking performance analytics and for marketing purposes. We and some of our third-party providers may use cookie data for various purposes. Please review the cookie settings below and choose your preference.
Used for the proper function of the website
Used for monitoring website traffic and interactions
Cookie Settings
Cookies and similar technologies are used on this website for proper function of the website, for tracking performance analytics and for marketing purposes. We and some of our third-party providers may use cookie data for various purposes. Please review the cookie settings below and choose your preference.
Strictly Necessary: Used for the proper function of the website
Performance/Analytics: Used for monitoring website traffic and interactions
Evaporation is a critical factor that must be considered while concrete is poured in hot weather conditions. If the rate of evaporation is high, concrete surface can lose water quickly, leading to workability issues and plastic shrinkage cracks. The post How to Estimate Rate of Evaporation on Concrete Surface?
6 Quick Tips for Calculating Concrete Yield. When pouring concrete, it's important to make sure you know all the variables involved and calculate with them in mind. Here's how to accurately estimateconcrete yield with construction tech. Elizabeth Manning. Tue, 11/17/2020 - 16:48.
Measurement of Reinforced Concrete Works: 1. Concrete in Structural members, such. How To Guide Material EstimationEstimation' The Quantities can be rounded off to the nearest two decimals.
How to control wastage of concrete at site? While estimating quantity of concrete for particular structural work, we normally consider 3-5% as. ConcreteConcrete Technology How To Guide Work Procedures Tips'
The size of movement depends upon the change in temperature and the coefficient of thermal expansion o f concrete. The size of movement depends upon the change in temperature and the coefficient of thermal expansion o f concrete.
Cracks in concrete beams due to increased shear stress 2. Cracks in concrete beams due to corrosion or insufficient concrete cover 3. Cracks parallel to main steel in case of corrosion in beams 4.
When the formwork is erected the concrete can be poured. When the concrete has reached the required strength the formwork can be poured. If the steel had been placed too close to the surface and the concrete had been poured then over time the steel may become exposed to moisture and corrosion will commence.
Use of Precast Concrete in frames: There are two main types of precast building frame. Use of Precast Concrete for Floors: Each year the industry makes about 5 million square meters of precast floor slabs. Structural frames are mainly used for offices, car parks and retail developments.
Upon wetting, concrete tends to expand. These moisture-induced volume changes are a characteristic of concrete. If the shrinkage of concrete could take place without any restraint, the concrete would not crack.
The benefits of using steel fibres in concrete are as follows: 1. It is generally not possible to achieve the same area of reinforcement to area of concrete using steel fibres as compared to using a network of reinforcing bars of wires.
There is no grout loss, such as that from badly fitting formwork, which results in poor quality concrete like shown below. By careful selection of materials and finishing processes, a wide range of high quality finishes can be obtained.
Nominal Mixes In the past the specifications for concrete prescribed the proportions of cement, fine and coarse aggregates. However, due to the variability of mix ingredients the nominal concrete for a given workability varies widely in strength.
Cracks in reinforced concrete columns due to Steel Corrosion (cracks parallel to steel bars) 2. Cracks in reinforced concrete columns due to shrinkage of concrete 3. Cracks in reinforced concrete columns due to shrinkage of concrete 3. Cracks in reinforced concrete columns due to increased load on the slab 4.
This method is used where large quantity of concrete work is involved at greater height, where other means of transporting is not easy to do. This method is used where large quantity of concrete work is involved at greater height, where other means of transporting is not easy to do.
It has many advantages when compared to the normal conventional concrete. The density is considerably reduced by using fly ash based cellular lightweight concrete than normal concrete and at the same time, the strength is not affected by appropriate design mix.
WHY WE TEST CONCRETE SRTRENGTH AFTER 28 DAYS? Tweet Why do we test concrete compressive strength after 28 days? The table below shows the compressive strength gained by concrete after 1, 3, 7, 14 and 28 days with respect to the grade of concrete we use.
There are two ways of overcoming this problem: Embed another material in the concrete which is strong in tension – reinforced concrete Remove the tension altogether – by arching or prestressing. In practice, reinforced concrete beams are designed on the assumption that cracks will occur under their service loads.
These are the environments to which the concrete will be exposed during its working life. No Environment Exposure Conditions 1 Mild Concrete surfaces protected against weather or aggressive conditions, except those situated in coastal area. Table below shows exposure conditions of these environments.
The concrete shall be deemed to comply with the strength requirements if: a) every sample has a test strength not less than the characteristic value;or b) The strength of one or more samples though less than the characteristic value, is in each case not less than the greater of : 1) The characteristic strength minus 1.35
The following figures illustrate the precast concrete process: 1. The individual components are prefabricated off site then taken to site where they are erected. The individual components are prefabricated off site then taken to site where they are erected.
Following are the cases, which affect creep in concrete: When the aggregate volume is increased, creep will be less as the aggregate is more rigid than the cement paste. Water within the hardened cement paste is forced to more as a result of the applied load.
in dry conditions), it should be suitable for use in concrete. Aggregates: Quality of aggregates, its size, shape, texture, strength etc determines the strength of concrete. The presence of salts (chlorides and sulphates), silt and clay also reduces the strength of concrete.
Formwork pressures are function of height (including the height from which concrete is dropped into the forms) and are affected by concrete workability, rate of stiffening and rate of placing. Exceeding this limit may lead to unacceptable formwork deflections, loss of grout / concrete at joints, or even collapse.
Advantages of Concrete Shells Like the arch, the curved shapes often used for concrete shells are naturally strong structures, allowing wide areas to be spanned without the use of internal supports, giving an open, unobstructed interior.
Cleanliness: when repairing concrete, care must be taken to remove any dirt or dust that will prevent the repair concrete bonding with the parent concrete. Cleanliness: when repairing concrete, care must be taken to remove any dirt or dust that will prevent the repair concrete bonding with the parent concrete.
WHAT IS PRECAST CONCRETE? Tweet Precast concrete is cast under factory controlled conditions and not erected on site until it is fully hardened. Just like in-situ concrete, precast concrete can be plain, reinforced or prestressed concrete. No related posts.
Procedure for measuring bulk density of concrete is as per IS 1199 – methods of sampling and analysis of concrete. Procedure for measuring bulk density of concrete is as per IS 1199 – methods of sampling and analysis of concrete. ii) Fill the cylindrical measure with concrete as soon as practicable after mixing.
Related posts: SELF COMPACTING CONCRETE WITH TESTS TESTS ON HARDENED CONCRETE CHEMICAL TESTS ON CONCRETE STRUCTURES COMMON TESTS ON THE FRESH CONCRETE Removing concrete slab to build wood deck but worried about water entering basement? Tweet Loading GET LATEST TOPICS IN YOUR EMAIL- SUBSCRIBE NOW.
It is new technique involved in the civil engineering.Reactive powder concrete in made by replacing the conventional sand and aggregate by grounded quartz less than300 micron size, silica fume, synthesized precipitated silica ,steel fibers about 1 cm in length and 180 micron in diameter.
Advantages that make precast concrete cladding such an appealing option are: Durability: Assuming the panel design has been carried out with proper thought for rainwater flow over the surface of the building, it will weather well and not require frequent cleaning.
The stress strain curve of concrete lies between those of the aggregate and the cement paste. The aggregate is more rigid than the cement paste and will therefore deform less (i.e. have a lower strain) under the same applied stress. The aggregate is more rigid than the cement paste and will therefore deform less (i.e.
NEVER accept a lump sum estimate for a workorder/project without a full detailed line-item estimate and review of line-times and quantities. Fully audit cost estimate and actual cost information. The post JOC Program Line-item Estimating appeared first on 4BT. Verify all aspects of the direct work (e.g.,
We organize all of the trending information in your field so you don't have to. Join 116,000+ users and stay up to date on the latest articles your peers are reading.
You know about us, now we want to get to know you!
Let's personalize your content
Let's get even more personalized
We recognize your account from another site in our network, please click 'Send Email' below to continue with verifying your account and setting a password.
Let's personalize your content