What Is A Chartered Quantity Surveyor?

What Is A Chartered Quantity Surveyor?


Members and Fellows of the RICS entitled to use the designation (and a number of variations such as "Chartered Building Surveyor" or "Chartered Quantity Surveyor" or "Chartered Civil Engineering Surveyor" depending on their field .

How to determine the size of elastomeric bearings?

How to determine the size of elastomeric bearings?

 For elastomeric bearing, the vertical load is resisted by its compression while shear resistance of the bearing controls the horizontal movements.

The design of elastomeric bearings are based on striking a balance between the provision of sufficient stiffness to resist high compressive force and the flexibility to allow for translation and rotation movement. The cross sectional area is normally determined by the allowable pressure on the bearing support. Sometimes, the plan area of bearings is controlled by the maximum allowable compressive stress arising from the consideration of delamination of elastomer from steel plates. In addition, the size of elastomeric bearings is also influenced by considering the separation between the structure and the edge of bearing which may occur in rotation because tensile stresses deriving from separation may cause delamination. The thickness of bearings is designed based on the limitation of its horizontal stiffness and is controlled by movement requirements. The shear strain should be less than a certain limit to avoid the occurrence of rolling over and fatigue damage. The vertical stiffness of bearings is obtained by inserting sufficient number of steel plates. 

What are the advantages of assigning the central pier and the abutment as fixed piers?

 What are the advantages of assigning the central pier and the abutment as fixed piers? 

For abutment pier to be assigned as fixed pier while the bridge is quite long, the longitudinal loads due to earthquake are quite large. As the earthquake loads are resisted by fixed piers, the size of fixed piers will be large and massive. In this connection, for better aesthetic appearance, the selection of abutment as fixed piers could accommodate the large size and massiveness of piers. Normally abutments are relatively short in height and for the same horizontal force, the bending moment induced is smaller.

For the central pier to be selected as the fixed pier, the bridge deck is allowed to move starting from the central pier to the end of the bridge. However, if the fixed pier is located at the abutment, the amount of movement to be incorporated in each bearing due to temperature variation, shrinkage, etc. is more than that when the fixed pier is located at central pier. Therefore, the size of movement joints can be reduced significantly. 

Civil engineering Short Question

What is the purpose of the gap in the road on this bridge?

Purpose of the gap in the road is to allow the road to expand and contract with temperature changes without causing damage or deformation to the road.

What is a projection line?

Projection line is the way, in which the earth is shown on a flat piece of Paper.

What are moment of inertia and its importance in civil engineering?

The moment of inertia measures the opposition any kind of body will have against a certain momentum (along that same axis) trying to rotate that body.

What is the absolute pressure scale?

Absolute pressure is calculated from a vacuum (0 PSI) and atmospheric pressure is14.7PSIa or 14.7 PSI above a vacuum 1PSI on a tire pressure gauge is called 1PSIg = 15.7PSIa 10PSIg=24.7PSIa 100PSIg=114.7PSIa etc.

What is diversion tunnel in a dam?

When a dam is to be built, a diversion tunnel is usually bored through solid rock next to the dam site to byPAss the dam construction site. The dam is built while the river flows through the diversion tunnel.

How do you maintain water pressure?

If you have water pressure and wish to maintain it, do not cause flow in the line, which will reduce pressure due to friction. To keep pressure up, reduce friction by increasing the line size or eliminating some other restriction.

 Why does the pressure increase under soil?

Soil pressure increases with depth due to the overburden or self-weight of the soil and due to loads imposed upon the soil.
For example, the pressure variation below the depth of soil is linear and the relation is given by pressure = unit wt * depth. As depth increases, there will be a linear increase in the soil pressure.

Why should curing not be done by pounding and polythene sheets?

Why should curing not be done by pounding and polythene sheets?

The primary purpose of curing is to reduce the heat loss of concrete that is freshly placed to the atmosphere and in order to reduce the temperature gradient across the cross-section of the concrete. Pounding is not preferred for curing as this method of thermal curing is greatly affected by cold winds. In addition to that in pounding large amounts of water is used and has to be disposed off from the construction sites. Polythene sheets are used on the basis that it creates an airtight environment around the concrete surface henceforth reducing the chances of evaporation over fresh concrete surfaces. But the usage of polythene can be a drawback as it can be easily blown away by winds and also the water lost by self-desiccation cannot be replenished.

Why should pumping be not used in case of concreting works?

Why should pumping be not used in case of concreting works?

During the pumping operation the pump exerted pressure must overcome any friction between the pumping pipes and the concrete, also the weight of the concrete and the pressure head when the concrete is placed above the pumps. Since only water is pump able, all the pressure generated is by the water that is present in the concrete. The major problem due to pumping are segregation effects and bleeding. In order to rectify and reduce these effects, generally the proportion of the cement is increased in order to increase the cohesion , which leads to the reduction of segregation and bleeding. Also if a proper selection of the aggregate grading can vastly improve the concrete pump ability.

What reinforcements are used in the process of prestressing?

What reinforcements are used in the process of prestressing?

The major types of reinforcements used in prestressing are:
> Spalling Reinforcement: The spalling stresses leads to stress behind the loaded area of the anchor blocks. This results in the breaking off of the surface concrete. The most likely causes of such types of stresses are Poisson`s effects strain interoperability or by the stress trajectory shapes.
> Equilibrium reinforcements: This type of reinforcements are required where several anchorages exist where the prestressing loads are applied in a sequential manner.
> Bursting Reinforcements: These kinds of stresses occur in cases where the stress trajectories are concave towards the line of action of load. In order to reduce such stresses reinforcements in the form of bursting is required.

Why are steel plates inserted inside bearings in elastomeric bearings?

Why are steel plates inserted inside bearings in elastomeric bearings?

In order to make a elastomeric bearing act/ function as a soft spring it should be made to allow it to bulge laterally and also the stiffness compression can be increased by simply increasing the limiting amount of the lateral bulging. In many cases in order to increase the compression stiffness of the bearing the usage of metal plates is made. Once steel plates are included in the bearings the freedom of the bulge is restricted dramatically, also the deflection of the bearing is reduced as compared to a bearing without the presence of steel plates. The tensile stresses of the bearings are induced into the steel plates. But the presence of the metal plates does not affect the shear stiffness of the bearings.

What do you understand by “preset” during the installation process of bridge bearings?

What do you understand by “preset” during the installation process of bridge bearings?

During the installation of bridge bearings the size of the upper plates is reduced to save the material costs. This process is known as preset. Generally the upper bearing plate comprises of the following components:
> Length of bearing
> 2 x irreversible movement.
> 2 x reversible movement.
The bearing initially is placed right in the middle point of the upper bearing plate. No directional effects of irreversible movement is considered. But since the irreversible movement usually takes place in one direction only the displaced direction is placed away from the midpoint. In such cases the length of the upper plate is equal to the length of the length of the bearing + irreversible movement + 2 x reversible movement.

Describe briefly the various methods of concrete curing.

Describe briefly the various methods of concrete curing.

Curing is the process of maintaining the moisture and temperature conditions for freshly deployed concrete. This is done for small duration of time to allow the hardening of concrete. The methods that are involved in saving the shrinkage of the concrete includes:
(a) Spraying of water: on walls, and columns can be cured by sprinkling water.
(b) Wet covering of surface: can be cured by using the surface with wet gunny bags or straw
(c) Ponding: the horizontal surfaces including the slab and floors can be cured by stagnating the water.
(d) Steam curing: of pre-fabricated concrete units steam can be cured by passing it over the units that are under closed chambers. It allows faster curing process and results in faster recovery.
(e) Application of curing compounds: compounds having calcium chloride can be applied on curing surface. This keeps the surface wet for a very long time.

What are the steps involved in the concreting process, explain?

What are the steps involved in the concreting process, explain?

The major steps involved in the process of concreting are as follows:
1. Batching
2. Mixing
3. Transporting and placing of concrete
4. Compacting.

> Batching: The process of measurement of the different materials for the making of concrete is known as batching. batching is usually done in two ways: volume batching and weight batching. In case of volume batching the measurement is done in the form of volume whereas in the case of weight batching it is done by the weight.
> Mixing: In order to create good concrete the mixing of the materials should be first done in dry condition and after it wet condition. The two general methods of mixing are: hand mixing and machine mixing.
> Transportation and placing of concrete: Once the concrete mixture is created it must be transported to its final location. The concrete is placed on form works and should always be dropped on its final location as closely as possible.
> Compaction of concrete: When concrete is placed it can have air bubbles entrapped in it which can lead to the reduction of the strength by 30%. In order to reduce the air bubbles the process of compaction is performed. Compaction is generally performed in two ways: by hand or by the use of vibrators.

Civil Engineering short Questions

What are the main reasons of building collapse?
There are several reasons for building collapse. Passage of time is the main reason. Also, weak foundations, natural calamities like earthquakes, hurricanes, etc., are the major reasons for building collapse. Bombing and destruction is also another major reason.

State the applications of modulus of elasticity.
Modulus of elasticity is related to the flexibility of the material. The value of modulus of elasticity is pretty important in case of deflection of different materials used in building construction.

How are the freeway bridges built?
The traffic that is likely to go over the bridge at a time is estimated and the cement, rocked with rebar stanchions is placed over the freeway to build a bridge. Off-ramp from freeway to the bridge and on-ramp from the bridge to the freeway are constructed. Cement slabs are used to build a platform.

What is the basic difference in absorption, adsorption, and sorption?
Absorption refers to the phenomenon where an atom, molecule or ions enter any bulk phase like gas, solid or liquid. Absorption refers to the phenomenon where energy of photon is transferred to other entity.
Adsorption is similar to absorption. It refers to the surface rather than a volume. Adsorption takes place when the gas or liquid solute accumulates on the surface of solid. A substance diffuses in liquid or solid to form a solution.

Civil Engineering Short Questions

How do you measure concrete? 
Cubic feet, Cubic yards, Cubic Meter


Which is stronger solid steel rod or hollow steel pipe? 
On a per pound basis, steel pipe is stronger in bending and is less likely to buckle in axial compression.

What is braced excavation all about? 
Excavations are braced to prevent the cave-in of surrounding unstable soil.

What is the meaning of soil reinforcement? 
Soil reinforcement is the act of improving soil strength to enable it support or carry more load.

Two common examples are:

a) Mixing a soil amendment such as lime into weak clayey soil and re-compacting to improve soil-bearing capacity (often done under the road base in highway construction)

b) Installing plastic or composite webbing layers (called geo-grid material) alternating with compacted soil to produce a stronger sloped soil structure (often done on steep roadway embankments to improve strength and stability)

What is aggregate? 
Aggregate is the component of a composite material used to resist compressive stress.

What year was the keystone power plant in Indiana County constructed? 
1967 began commercial operation on unit 1.

What is the force exerted by the Tacoma narrows bridge? 
The force exerted to the Tacoma narrows bridge was initially the wind resistance. The wind resistance caused the whole bridge to act as a system with forced vibration with damping.

Types of Formwork (Shuttering) for Concrete Construction:

Types of Formwork (Shuttering) for Concrete Construction:

Timber Formwork:

Timber for formwork should satisfy the following requirement:

It should be

1. well seasoned
2. light in weight
3. easily workable with nails without splitting
4. free from loose knots

Timber used for shuttering for exposed concrete work should have smooth and even surface on all faces which come in contact with concrete.

A good formwork should satisfy the following requirements:

A good form work should satisfy the following requirements:

1. It should be strong enough to withstand all types of dead and live loads.
2. It should be rigidly constructed and efficiently propped and braced both horizontally and vertically, so as to retain its shape.
3. The joints in the form work should be tight against leakage of cement grout.
4. Construction of form work should permit removal of various parts in desired sequences without damage to the concrete.
5. The material of the formwork should be cheap, easily available and should be suitable for reuse.
6. The formwork should be set accurately to the desired line and levels should have plane surface.
7. It should be as light as possible.
8. The material of the formwork should not warp or get distorted when exposed to the elements.
9. It should rest on firm base.

Quantity of Cement and Sand Calculation in Mortar

Quantity of Cement and Sand Calculation in Mortar

Quantity of cement mortar is required for rate analysis of brickwork and plaster or estimation of masonry work for a building or structure. Cement mortar is used in various proportions, i.e. 1:1, 1:2, 1:3, 1:4, 1:6, 1:8 etc.

Calculation of quantity of cement mortar in brickwork and plaster:

For the calculation of cement mortar, let us assume that we use 1m3 of cement mortar. Procedure for calculation is:

1. Calculate the dry volume of materials required for 1m3 cement mortar. Considering voids in sands, we assume that materials consists of 60% voids. That is, for 1m3 of wet cement mortar, 1.6m3 of materials are required.

2. Now we calculate the volume of materials used in cement mortar based on its proportions.

Let’s say, the proportion of cement and sand in mortar is 1:X, where X is the volume of sand required.

Then, the volume of sand required for 1:X proportion of 1m3 cement mortar will be

3. Volume of cement will be calculated as:

Since the volume of 1 bag of cement is 0.0347 m3, so the number of bag of cement will be calculated as:

Example:

For cement mortar of 1:6, the quantity calculated will be as below:

Sand quantity:

Quantity of cement (in bags):

Volume of cement = 

Procedure: Compressive Strength Test of Concrete Cubes

Procedure: Compressive Strength Test of Concrete Cubes

For cube test two types of specimens either cubes of 15cm X 15cm X 15cm or 10cm X 10cm x 10cm depending upon the size of aggregate are used. For most of the works cubical moulds of size 15cm x 15cm x 15cm are commonly used.

This concrete is poured in the mould and tempered properly so as not to have any voids. After 24 hours these moulds are removed and test specimens are put in water for curing. The top surface of these specimen should be made even and smooth. This is done by putting cement paste and spreading smoothly on whole area of specimen.

These specimens are tested by compression testing machine after 7 days curing or 28 days curing. Load should be applied gradually at the rate of 140 kg/cm2 per minute till the Specimens fails. Load at the failure divided by area of specimen gives the compressive strength of concrete.

Following are the procedure for testing Compressive strength  of Concrete Cubes

Apparatus for Concrete Cube Test

Preparation of Concrete Cube Specimen

The proportion and material for making these test specimens are from the same concrete used in the field.

Specimen

6 cubes of 15 cm size Mix. M15 or above

Mixing of Concrete for Cube Test

Mix the concrete either by hand or in a laboratory batch mixer

Hand Mixing

1. Mix the cement and fine aggregate on a water tight none-absorbent platform until the mixture is thoroughly blended and is of uniform color
2. Add the coarse aggregate and mix with cement and fine aggregate until the coarse aggregate is uniformly distributed throughout the batch
3. Add water and mix it until the concrete appears to be homogeneous and of the desired consistency

Sampling of Cubes for Test

1. Clean the mounds and apply oil
2. Fill the concrete in the molds in layers approximately 5 cm thick
3. Compact each layer with not less than 35 strokes per layer using a tamping rod (steel bar 16mm diameter and 60cm long, bullet pointed at lower end)
4. Level the top surface and smoothen it with a trowel

Compressive Strength Formula

Compressive Strength Formula

Compressive strength formula for any material is the load applied at the point of failure to the cross-section area of the face on which load was applied.

Compressive Strength = Load / Cross-sectional Area

Compressive Strength Definition

Compressive Strength Definition

Compressive strength is the ability of material or structure to carry the loads on its surface without any crack or deflection. A material under compression tends to reduce the size, while in tension, size elongates.

Advantages and Disadvantages of Prestressed Concrete

Advantages of Prestressed Concrete

The major advantages of Prestressed Concrete are:

1. The prestressing of concrete by using high tensile steel improve the efficiency of the materials
2. The prestressing system works for a span greater than 35m.
3. Prestressing enhance shear strength and fatigue resistance of concrete
4. Dense concrete is provided by prestressing systems thus improving the durability
5. Best choice for the construction of sleek and slender structures.
6. Prestressing helps to reduce the dead load of the concrete structure
7. Prestressed concrete remains uncracked even at service load conditions which proves the structural efficiency
8. Composite construction by using the prestressed concrete unit and cast-in-unit derives the economical structure

Disadvantages of Prestressed Concrete

1. Higher material costs
2. Prestressing is an added cost
3. Formwork is more complex than for RC (flanged sections, thin webs) – thus, precast not as ductile as RC