Thursday, June 30, 2016
A bridge refers to a structure that arranges a passage over a hurdle devoid of closing the way underneath. The necessary passage will be intended for a road, a railway, pedestrians, a canal or a pipeline. The hurdle to be spanned may be a river, a road, railway or a valley.
Categorization of Bridges
Category of Bridges (based on form (or) type of superstructures)
1. Slab bridge
2. Beam bridge
3. Truss bridge
4. Arch bridge
5. Cable stayed (or )suspended bridge
Category of bridges (based on construction material of superstructure)
1. Timber bridge
3. Stone bridge
4. R.C.C bridge
5. Steel bridge
6. P.C.C bridge
7. Composite bridge
8. Aluminum bridge
Category of bridges (As per inter-span relationship)
1. Simply supported bridge
2. Cantilever bridge
3. Continuous bridge
Classification of bridges (Following the placing of the bridge floor compared with superstructures)
1. Deck through bridge
2. Half through or suspension bridge
Categorization in terms of method of connection of various part of superstructures
1. Pinned connection bridge
2. Riveted connection bridge
3. Welded connection bridge
On the basis of length of bridge
1. Culvert bridge(less than 6 m)
2. Minor bridge(less than 6 m-60m)
3. Major bridge(more than 60 m)
4. Long span bridge(more than 120 m)
On the basis of function
1. Aqueduct bridge(canal over a river)
2. Viaduct(road or railway over a valley or river)
3. Pedestrian bridge
4. Highway bridge
5. Railway bridge
6. Road-cum-rail or pipe line bridge
For more information, visit this link
Wednesday, June 29, 2016
This construction video is extracted from an exclusive presentation by Raafat El-Hacha, Associate Professor, University of Calgary, Calgary, AB, Canada, that focused on the tolerable performance of concrete bridges as well as their components when based on rigorous environmental conditions.
The session covers a range of technical features like strength of concrete members, techniques for checking performance, appraisal methodologies, damage appraisement, and structural restoration supported with both experimental and analytical examinations. The session highlighted current research outcomes as well as offers the scope to talk about existing confrontations and technical issues. The session is ideal for the professionals who play a vital role in tomorrow’s bridge design and construction, along with practicing engineers, government officials, and academics to obtain crucial information.
Tuesday, June 28, 2016
The boundary elements, whether regular or hidden, are reinforced based on the rules which are assigned to columns.
For reinforcing of the wall body, there are two parallel grates (known as curtains) one at each face. They are retained collectively through an ‘S’-shaped vertical bar. The vertical and horizontal grate rebars should contain a diameter at least identical to Ø8 .The reinforcement with “S” shape must be higher or equivalent to 4Φ8/m2
To avoid cracked surfaces e.g. in pool sides, narrow spaced grates should be applied having the lower possible rebar diameter.
To avoid cracked surfaces e.g. in pool sides, narrow spaced grates should be applied having the lower possible rebar diameter.
The ‘S’- shaped reinforcement
The ‘S’-shaped bar offers anti-buckling restraint to the longitudinal reinforcement. Besides, it makes sure that the vertical and the horizontal rebars will progress work jointly regardless of a potential concrete spalling that may occur due to an strong earthquake.
The ‘S’-shaped link is developed with one closed corner at an angle similar to 180°, or 135° and the other corner bent at an angle equivalent to 90°. This is crucial for positioning it without any difficulty. Once it is applied, the second corner must be also bent at an angle at least equivalent to 135°.
It is acceptable to apply soft steel to have the ability to bent the ‘S’-shaped reinforcement manually.
If the vertical rebars are positoned in an interior layer, then the ‘S’-shaped link must detain the horizontal rebars to the region that they bisect with the vertical ones or get around both horizontal and vertical rebars simultaneously.
On the other hand, in an rectangular shear wall, the reinforcement of the boundary column and the distribution rebars of the wall’s body is carried out as two ‘Γ’ shaped parts. Folded mesh is applied to develop the ‘Γ’ shaped parts.
Ref : debug.pi.gr
|Image Courtesy - debug.pi.gr|
Monday, June 27, 2016
This construction video is based on Construction Master 5 contractor calculator. By watching this video one can learn how 5’s stair function of construction master can save significant time for building professionals for computation and stair table lookups.
Construction Master 5 contractor calculator's in-built stair layout key can provide streamlined solution to develop your next stairs together with number of risers, riser height, number of treads, tread widths, stringer length, angle of incline and total run of the stairs.
Get trained how to utilize this construction math power tool to execute all your design, estimating and jobsite calculations easily, instantly and perfectly to make your productivity and profitability better.
This construction calculator offers the following features :-
Dimensional Math and Conversions
• Performs and transforms among building dimensional formats: Yards, Feet-Inch-Fractions, Decimal Feet-Inches and Metric – together with Area and Volume
• Detect Weight per Volume Committed Functions
• Workout Stair for Risers, Treads, Stringer Length and Incline Angle; shows Run and Rise
• Custom Rafter Function offers Common Rafters, Regular and Irregular Hips, Valleys and Jacks. Jack Rafter feature offers comprehensive solutions for Normal and Asymmetrical Pitch roofs. Exposes On-center spacing.
• Solutions for Circles, Arcs, Columns, Pillars, Windows, Post-holes and more
• Rake-Wall function defines Stud Length for any On-center Spacing, in Ascending or Descending order
• Board Feet Lumber calculation
To get more information, visit this link
Friday, June 24, 2016
Water to cement ratio refers to ratio related to the weight of water and the weight of cement which are the essential part of a fresh concrete mix. The stability of compacted concrete mainly relies on water to cement ratio. Cured concrete strength is based on the following two main aspects :-
1. Water to cement ratio
2. Degree of compaction
Air voids in concrete happen on the basis of the water to cement ratio. If the weight of water rises, air voids is also raised. Due to this circumstance, the concrete strength is also decreased. Solidified concrete includes about 1% of air voids. If a concrete is in a solidified condition, strength is contrarily proportionate to the water/cement ratio.
The following figure indicates that validity range of water to cement ratio is very restricted. Compressive strength will be higher, when water to cement ratio is down. The starting of the curve is based on the existing methods of compaction (that is either accomplished with vibrators or compaction by hand). If large size aggregates are applied with low water to cement ratio and greater contents of cement then it reveals deterioration of the concrete strength.
So, if there exist a low water to cement ratio in a fresh mix than as soon as the concrete is solidified, water/cement fails to keep a greater concrete strength. These conditions occur due to the formation of tensile stresses for shrinkage and creep. It results in cracking of the cement or losing bonds (that happens amid cement and aggregates) just as aggregates attempt to control the tensile stresses.
So, low water to cement ratio may cause major issues in solidification of concrete. If water to cement ratio is low in a fresh mix, then less water is available for the hydration of cement. Hence, some amount of cement paste stays un-hydrated that causes internally tension in concrete as well as feeble bond. The strength that might be established under the present situation is mainly based on the following four factors :-
1. Water to cement ratio
2. Cement to aggregate ratio
3. Maximum aggregate size
4. Physical properties of aggregates
The factors (2,3 and 4) are not so vital whereas factor (1) is the most crucial factor. Since strength of concrete is affected by the strength of mortar, bond of mortar with aggregates and coarse aggregates strength.
To get more information, visit this link
Thursday, June 23, 2016
Brick, cement, sand and stone chips are considered as the most vital construction materials which are generally found in all types of Civil engineering construction ranging from brickwork to floor finishing.
So, an accurate quality control should be initiated in every phase specifically at the initial phase where it is essential to choose proper materials for a construction type. In order to determine the quality (if the any material is good or worst) of the primary construction materials like Brick, Cement, Sand and Stone Chips, the materials should be examined visually through jobsite test.
Verification of Brick :-
The following field tests are necessary to decide whether a Brick is good or not:-
1. A good brick must contain perfect shape and customary specified size, the edges of the brick should be sharp, the brick should be free from any cracks and fissures.
2. The brick should be colored with copper red color. A yellowish shade on brick denotes that it is going through burning process and therefore contains inferior strength. If a brick is made of dark blackish blue color then it denotes the brick is burnt excessively and is breakable in nature.
3. When a brick is collided with a hammer or against another brick, there should be a clear metallic ringing sound that indicates that it is not dull.
4. A newly broken brick should display a standardized compact structure devoid of containing any lumps.
5. If a brick is fallen from about a height of 1m on a solid ground or on another brick, it should not break.
6. If a brick is dented with finger nail it should not provide any mark on the brick.
7. A perfect quality brick (1st Class) should not consume water by not over 20% of its own Dry weight when submerged in water for a period of 24 Hours.
For getting further information, visit this link
Tuesday, June 21, 2016
Registration is now open for the next class of Collision Industry Information Assistance (CIIA) is going to conduct its basic estimating collision repair training course and one can register for the course online.
This fundamental estimating course is specifically planned to facilitate shop or office employees, new estimators and insurance company staff to simplify their estimating process for collision damage on cars and light trucks in Ontario.
The course covers various topics like introduction to estimating, good perception on vehicle construction, basics of estimate writing, gather knowledge on collision manuals, added charges and collision damage analysis.
The course fee is $550 + HST, for each person for CIIA members and $750 + HST, for each person for non-members. One has to make prior payment to attend the course.
Employers will be liable for a total rebate of two-thirds of the course fees. To register their seat, students must contact the CIIA office at 1-866-309-4272 or e-mailing email@example.com.
The forthcoming courses will be organized in two full days in Ottawa, Burlington and Toronto.
OTTAWA: Friday June 24 and Saturday June 25
8:30 a.m. to 5 p.m.
BURLINGTON: Friday July 22 and Saturday July 23
8:30 a.m. to 5 p.m.
TORONTO: Friday September 23 and Saturday September 24
8:30 a.m. to 5 p.m.
Monday, June 20, 2016
Usually, the contractor should take responsibility with all essential steps to track and resist cracking in fresh hydrating concrete, devoid of the size or volume of the pour. The steps should be approved by the Engineer and ensure that extreme surface crack width on hardened concrete measure instantly after the pour does not surpass 0.004 times the nominal cover of the primary reinforcement.
The contractor will be responsible for and offer sanctioned instrumentation for measuring the variation of internal temperature in large pours. The extreme concrete temperature at the point of delivery usually shall not surpass the lower of either 37 degree C, or 6 degree C beyond the existing shade temperature compliant with the approvals of ACI. The limiting internal temperature differential measured over the maximum faces of concrete mass shall not go above 25 degrees C at any time.
Curing of hardened concrete will be done according to the curing specification. Usually, the element surface is not chilled to disperse heat from the concrete. Curing methods, like the drenching of heated concrete elements uncovered to long and direct radiation, which produce temperature gradients inside the concrete mass, are not recommended for application.
For big pours, the contractor will be liable for and take additional provisions to lessen concrete temperature gradient as well as check the loss of surface moisture. Such steps are described below :-
Maintaining all mix ingredients shaded where feasible to decrease their temperatures in the stockpile
Chilling of mixing water and/or substituting part or entire of the extra water with ice.
Lessening the cement content with the application of admixtures (but not lower that is essential for the stability)
Applying a cement having a inferior heat of hydration
Injecting liquid nitrogen once the concrete is blended
Limiting the time amid mixing and assigning of the concrete to below 2 hours
Delivering permitted surface insulation constantly over all uncovered surfaces to resist draughts as well as keep identical temperature with the concrete mass
Starting curing instantly once final tamping is done and carry on till the permitted surface insulation system is completely prepared
Providing shade to the concrete surface to resist heat obtained from direct radiation.
For more information, click on this link
Saturday, June 18, 2016
Climbing formwork denotes an innovative formwork toward vertical concrete structures that develops with the progression of the building. This type of formwork system is ideal for the construction of dams, towers, piers, pylons etc.
The process for setting up of this type of formwork is very complex and expensive. It offers streamlined solution for buildings which are either very iterative in form (like towers or skyscrapers) or necessitate a continuous wall structure (with the use of gliding formwork, a special type of climbing formwork).
Different types of climbing formwork available in the construction industries, which can be either displaced from time to time, or can even shift independently (typically on hydraulic jacks, essential for self-climbing and gliding formworks).
Give below some of the most recognized climbing formworks :-
CR-250: Powerful Climbing Bracket system intended for bigger formwork units. It is mainly applied for pouring of double-sided walls (piers, walls, etc.). The brackets are based on anchor cones, which were implanted in the concrete in earlier pouring phases.
KSP: KSP is ideal for lift and staircase shafts, hollow piers or other types of gaps where it is essential to support formwork panels. This system is usually integrated with customary climbing systems at the outside of the wall.
Friday, June 17, 2016
Structural Insulated Panels (SIPs) is a great substitute for R-30 (or higher) walls toward single and multifamily construction.
SIPs belong to a manufactured “sandwich” panel which are formed with two exterior faces of oriented-strand-board (OSB) wrapped with a core of stretched polystyrene foam insulation (EPS).
Based on the manufacturer and the needed properties of the final wall system, the material contained by the outer faces and the foam insulation core can differ. Alternate insulation cores consist of extruded polystyrene (XPS), polyisocyanurate and polyurethane. Besides OSB faces, there are other materials like plywood, straw board, and cement board.
Panels containing interior gypsum board or tongue-and-groove pine boards are also obtainable but these may be easily spoiled in transit. So, proper care should be taken while installing & handling them. The complete thickness of the foam core (and thus the R-value attained) is also adjustable and is normally available in dimensions.
Typical foam-core thicknesses are 3-1/2”, 5-1/2”, 7-3/8”, and 9-3/8”.
The complete, nominal R-value of a SIPs wall is a function of its thickness and the type of core insulation applied. Usually EPS foam is R-4 per inch, XPS is R-5 per inch, and polyisocyanurate and polyurethane are roughly R-6.5 per inch (the higher R-value cores are consistently more costly).
Building Design and Planning Considerations
In order to install SIPs successfully in a building project, proper plan should be set up to make the project panel-friendly.
Therefore, the design of the building should be simple in form devoid of any unnecessary jogs, bump-outs, non-90 degree angles, as well as the envelope openings are arranged to match with panel dimensions.
SIPs are applied virtually to any house design, but with a non-panel friendly plan, the amount of waste, internal posts, headers and structural panel slice lumber will rapidly count reducing the cost and performance advantage of a more improved design. The utilization of standard heights is correspondingly crucial in managing costs and eliminating waste. The availability of the largest panel is 8’ x 24’ (on the basis of the limits of obtainable OSB manufacturing), SIPs positioned horizontally contain a extreme wall height of 96”.
Similarly, SIPs positioned vertically contain a maximum width of 96”, but can be applied with full height to attain 8’, 9’, or even 10’ high walls.
Due to its more inflexible nature, cement board SIPs are more limited in dimension as compared to OSB SIPs, with usual sizes of 3’ x 8’, 3 x 9’, and 3’ x 10’ and are therefore always positioned vertically.
For more information, click on this link
Thursday, June 16, 2016
This construction article provides detailed guidelines for substituting shingle roof, setting new roof, extracting old roof as well as eliminating flashings.
The construction video will be useful to undertake repair, and precautionary maintenance, along with safeguarding and roof leak repair toward the industrial, and home residential buildings.
If your roof surpasses 20 years old and most of the shingles are severely defective or critically worn, it should be replaced immediately because through damaged roof water can seep under the shingles and rot the wood sheathing below.
Wednesday, June 15, 2016
This construction video will introduce you to some useful construction tips on how to lay 12 inch block perfectly for a brick wall.
There are various types of concrete blocks available for present construction industries. Generally standard 8" units is widely used that can make the greater part of the foundation. Other types range from single and double corner units, which offer a smooth square or rounded corner. There are also jamb blocks which can be used for developing a doorway.
Sash blocks are applied if it is required to form casement windows with an opening. Place header blocks at the top of a wall to provide space for roof supports or other construction supports.
If required, the specialty blocks can also be purchase. Alternatively your building blocks can also be customized to give a personal touch to your project.
Tuesday, June 14, 2016
If 4 litres of water is added with 1 cubic meter of newly blended concrete, the following result is obtained :-
1. Expand slump roughly 25 mm.
2. Lessen compacted strength around 1.5 to 2 N/mm2.
3. Enhance shrinkage potential nearby 10%.
If temperature of newly mixed concrete is enhanced by 1 degree celcius, the result will be as follow :-
1. Around 4 litres of water per cubic meter sustains identical slump.
2. Air content drops around 1%.
3. Compacted strength reduces approximately 1.0 to 1.5 N/mm2.
In case the air content of newly mixed concrete :-
1. Enhances 1% then compacted strength reduces roughly 0.5%.
2. Lessens 1% then produced result will reduce nearby 0.03 cubic meter per 1 cubic meter.
3. Lessen 1% then slump reduces nearly 12.5mm.
4. Drops 1% then strength reduces almost 10%.
Monday, June 13, 2016
This construction video provides some useful construction tips for setting up wood fence along with posts and pickets.
At first dig holes for the component fence, then arrange the posts. Initially compute the posts and trim as per length. Prior to placing the posts, include gravel for drainage. Adheres to local building codes to get the exact amount required. Now organize the posts in proper position, insert concrete and water. Fill to roughly 2'' from the surface.
As soon as the concrete is dried, and the posts are securely in position, set the stringers or rails. Arrange one rail for about each 2' of post height. Affix the rails to the outer side of the posts on the bottom, middle and top by screws. Ensure that the rails are leveled with your posts.
Once the rails are installed, finally set up the pickets. Affix the boards through a nail gun to every rail. The pickets should remain right next to each other. Verify to ensure that the pickets are level. For edges, overlay the pickets for a clear and uniform corner.
Thursday, June 9, 2016
Deanston Cooper is inviting applications for the position of a Quantity Surveyor who will perform a national civil engineering contractor located at Glasgow. Projects are worth £10 million contain include roads, bridges, groundworks, infrastructure works and sub stations.
Duties and Responsibilities :-
• To communicate with the operational management and provide suggestions on all matters regarding Contract and Commercial issues.
• To sustain correct financial control systems and report in each month on Cost/Value Reconciliation.
• To deal with and instruct on all financial aspects of contracts, certifying that valuations are optimized, validated and disbursed in time.
• To check advancement on site regularly and play a vital role in issuing essential notices according to contract processes and timescales.
• To organize cost predictions and value of all trades together with Preliminaries, monitor and report on same.
• To arrange Preliminaries budgets along with contract staff, supervise and report on same.
• Make sure that all quotations are cautiously examined and adhere to the specification confirming that the most competitive bids are attained.
• Make sure that monthly meetings are organized properly to settle variations and not kept pending to the final account stage.
• Make sure that quotations for supplementary works are perfect and acquired on time.
• To handle subcontractors accounts precisely and efficiently to augment contract performance.
• Procure competitive advantage
• Be present at progress and other meetings as required to exemplify the company’s interests.
• To work in tandem with the site management team, as necessary, safeguarding labour, materials and Sub-contractors to guarantee that contracts are executed timely and within budget.
• Well versed with HND Quantity Surveying
• Related experience obtained performing with another civil engineering contractor
• Very good spoken and written communication skills
• Outstanding analytical & problem solving skills
Salary is offered £48 000 together with other facilities like plus car / car allowance and pension.
Wednesday, June 8, 2016
A flat slab belongs to a one-way or two-way method that is condensed in the slab at the columns and load bearing walls known as ‘drop panels’. Drop panels are used as T-beams over the supports. They improve the shear capacity and the rigidity of the floor system below vertical loads, which consequently enhance the economical span range. Now-a-days, this type of construction is not recommended as the perimeter on economical spans is approximately 9.5 m for reinforced slabs and approximately 12 m for pre-stressed slabs. Reinforced flat slabs should be reasonably pre-cambered (not overdone) to manage deflection.
The primary features of a flat slab floor are a flat soffit, plain formwork and simple construction. The economical span ‘L’ of a reinforced concrete flat slab is roughly D x 28 for simply supported, D x 32 for an end span and D x 36 for an interior span. Prestressing the slab expands the economical span to D x 35, D x 40 and D x 45 correspondingly, where D denotes the depth of the slab exclusive of the drop panel.
Benefits and Drawbacks of Flat Slabs
• Uncomplicated formwork
• No beams—make things easier under-floor services outside the drops
• Lowest structural depth
• Generally no need of shear reinforcement at the columns.
• Moderate spans
• Usually not appropriate for supporting brittle (masonry) partitions
• Drop panels hinder in bigger mechanical ducting
• Vertical penetrations should prevent area around columns
• For reinforced flat slabs, deflection at the middle strip becomes complicated.
Tuesday, June 7, 2016
Now-a-days various residential constructions are based on either concrete slabs-on-grade or on concrete or masonry foundations. There are various types of foundations, each of which offers both the potency and solidity to sustain the weight of the structure, its contents and occupants, as well as wind and snow loads which are transmitted to the foundation through the structure.
Zachary Francis comes up with a useful construction video tutorial on Reinforcement of foundation walls and footers. By watching this construction tutorial you will gather knowledge on the following topics :-
• Who is responsible to set up steel in both the wall and the footer Sorts of steel should be utilized in light frame construction
Where to collect the information essential to operate the tablets
• Where should be the tablets utilized and how to ascertain the type of wall as well reinforcement for utilizing
• How important is the soil type and types of rebar utilized in different foundation types
A robust foundation together with perfectly set up footings of acceptable size to defend the structure and resist extreme settlement, is necessary for the satisfying performance of buildings along with raised floor systems.
Monday, June 6, 2016
Saturday, June 4, 2016
R.C.C. denotes Reinforced Cement Concrete, and in recent times it is considered as the primary Constructional Material to be utilized for developing various structural parts. Previously, high rise buildings were constructed with Pure Steel Structure but with the use of R.C.C., it becomes easier to obtain superior strength economically to resist any powerful imposing loads on structure.
R.C.C. is formed with two main diverse components like Concrete and Reinforcement involving Steel.
Why reinforcement is necessary?
Because of bending of a structure, one side of the structure has Neutral Axis Compresses and the other side is tensed. So both Compressive Stress and Tensile Stress grow in the structure from the Neutral Axis in the direction of the Extreme Fiber i.e. the external face of the structure in a cumulative manner according to magnitude of the stresses. So the Structure contains both Compressive and Tensile Stresses in it.
A Concrete can withstand Compressive Stresses efficiently but it can’t resist Tensile Stresses very well and it can only defy a very minute Tensile Stress. Therefore, to safeguard a structure and keep it in working condition to bear the Design Loads, the structural material should have the capability to resist both Tensile and Compressive Stresses. But the Concrete is not so powerful to combat the Tensile stress, so some steps should be initiated to provide something which can bear the Tensile Stresses established in Concrete. To make it possible, the Structural Member like Column, Beam, Slab etc are not constructed with Plain Concrete rather than Reinforced with Steel implanted in it to bear the Tensile Stresses developed.
Why Steel is applied as Reinforcement?
Because of the variation of temperature, the Concrete stretches and shrinks. Therefore, the material applied for Reinforcing will also stretch and shrink caused by the variation of temperature on the basis of their co-efficient of volumetric expansion. If the change of Volume of Concrete and implanted Reinforcement will not contain the similar amount at the surface of contact amid Concrete and Reinforcement, various types of stresses will form which can create cracking in concrete and lead to collapsing of the structure. After thorough research, It is established that the Co-efficient of Expansion of Concrete and Steel is nearly same. So with the variation of temperature, no differential Stresses will form and there will no cracks as well as collapsing of the structure.