The Goodness of Construction Machinery

Regardless of any scale in construction that might be, there is always be a heavy equipment to support it. We would not want to construct any structure that took ages to complete it, and required lots and lots of workforce in one time. Thus, the construction site would become crowded with human beings and will eventually create other problematic issues like health and environmental. The choices of construction equipment for any type of operations are important that would increase efficiency and profitability of the construction process.

Let’s take a look of the advantages of utilizing the construction machinery:

• Increase the rate of output through work progress with the best effective and efficient methods. The construction works is usually counted by volume of output or completion thus will be used to cover-up any other expenses or defects.
• Reduce the overall construction costs especially for large contracts. One particular cost that can be covered effectively is the labor cost, and besides the machinery can be use for the next project.
• Carry out activities which cannot be done manually or to do them more economically and much faster. The time and budget is always the most concerned matter in any site project.
• Eliminate the heavy manual work by human thus reducing fatigue and increase the productivity of manual workers. Technically speaking, all the hardship on construction works can be done without sacrificing or jeopardizing the human ‘engine’ that might brings hazard and health issues.
• Maintain the planned rate of production where there is a shortage of skilled or unskilled labor. Some of the heavy machinery would be able to replace human as the workforce at maximum capacity.
• Maintain the high quality standards often required by present-day design and specifications (technical standards). The technical standards like ASTM and BS required a strict compliance upon any works involving construction as it will ensure the safety of the users in the future.

The Selection Factors of Construction Machinery

How we go about selecting the best possible construction machinery that would give the finest results and cost effective? In general, there are 9 selection factors involved while construction equipments for any particular site project. This means the understanding of the machinery itself is essential for work effectiveness, promotes further productivity, and better overall quality.

The selection would normally depend on the followings:
Size of Operations
The size or scale of construction operation is pretty much determined by how much the excavation, how much the concrete, and how high the lifting would be especially at the project spot. One good example, if the proposed structure occupies the whole of the site it could eliminate the use of large batch concrete mixers, dumpers and cement storage silos.

Type of Operations
Any new or proposed work awarded to the main contractor shall be able to provide adequate machinery, especially if the works involving earthworks that require excavation and filling. As for the restoration work, it doesn’t require many construction equipment whereby most of the work can be execute with facilitate of skilled workers. Nonetheless, the machinery is still required regardless of any type of project.

The Construction Method
If the work executes on the site, there would be a complete set of machinery designated for that particular project with its own Method of Statement and Scope of Works. This is where most of the construction machinery shall be utilized at optimum capacity. The prefabricated works are normally done at the designated place or plant (in closed compound) that minimizes the usage of machinery but selective ones.

The Allowable Time Frame
If we talk about the allowable time frame of any project, the numbers of machinery will be an absolute advantage. The contract period and finishing date would be counted and brings a good reputation for the consultant and the contractor who involved in the project. In a road project, several sections can be workout effectively and efficiently at one time if the numbers of heavy and light machinery are sufficient.

Workforce Availability
The workforce will be locating the competent workers upon the type of plant and its operation. It must be operated by trained or skilled operators, and it would be an advantage if any operator capable of handling more than one type of machinery. Trained person for maintenance, especially the mechanics and schedule for the plant maintenance must be followed.

Ground or Soil Conditions
All the construction machinery that walks the Earth’s surface should consider the ground or soil condition. If the sites are wet, it requires a plant with caterpillar tracks (mostly with chain). And if the sites are dry, it is suitable for both track and wheeled vehicles or machinery.

Access to Project Site
No matter how the method of statement would be, sometimes the access path to the project site is not planned carefully and often overlooked. As an example, the congested town sites shall limit the use of many types of machinery and plant. The allowable weight and height of machinery to be transported to site would also affect the operations’ outcome.

The Safety Aspects
When the safety aspect becomes a must (it is now), the Health and Safety Department regulations should be followed by all staff at the workplace. Some equipments specially designed for safety purposes should be worn at all times (the PPE’s). If the construction equipment doesn’t fit the requirement as noted to be replace or danger for operation, it will not be allowed for use and removed from the site.

The Noise Emissions
Under the Health and Safety regulations at work provision is made for the protection of workers against noise. Local authority requirements should also be following especially if the project located at town or the residential housing. The types of construction machinery prohibited from the site use are the ones that emitted loud and disturbing noise. The number of hours for operation which may be carried out would also limit if certain machinery is required and the level of noise permitted during specific hours.

Buying or Hiring Construction Plants? What’s Best…

Either buying or hiring construction plants, it’s all depends on the scale of the construction project. Let’s look at the advantages side of having plants for what might be considered:

Advantage of Buying Plants

• In anytime of requirement, the plant is available for operation.
• Cost of idle time caused by inclement weather, work being behind planned programme or delay in deliveries of material will generally be less on owned plant than hired.
• The builders can apportion the plant costs to the various contracts using the plant if the capacity permitted.

Advantage of Hiring Plants

• Normally it is hired as required and used for short periods of contract.
• The hire firms are responsible for any repairs and replacements cost.
• The contractor is not left with expensive plant after completion of contract.
• In general, the hire rates can only include the operator, fuel and oil.

The Construction Equipment and Earthworks Relationship

The earthworks involved ground or soil works and often times considered as the major works especially the road or highway projects. The road construction machinery becomes the number one major ‘workforce’ at construction sites which requires only the skilled operators, and able to execute difficult and enormous task.

Process Involved in Earthworks
Earthworks involved two major processes, which are the cut and fill of soil. The cut aspect comprises the excavation of existing land to the suitable formation or reduced level. The fill aspect comprises the work of formation buildup of embankments. As a result of excavation works, the disposal of soil can be used as fill materials if suitable or transferred to the located dump site for treatment or total removal. The suitable fill materials would be used by the layer-by-layer method and compacted properly until reach the required formation level (theSubgrade Layer). The construction machinery such as excavator and bulldozer often used and works best for every possible ground condition.

The Excavation Works
There are 3 factors of excavation works for consideration:
1. Type of Excavated Material
Soil as we know it contains lots of variation in terms of textures and constituents. The soil investigation should be able to tell us what would be the ‘real’ situation that you could expect upon construction.

Bulking Factor = Volume After excavation / Volume Before Excavation
Shrinkage Factor = Volume After compaction / Volume Before Excavation

2. The Diggability
Diggability is defined as the ease of ground or soil digging. The used of construction equipment sometimes referred diggability as guidelines and from here, the exact type of machine is known (or best for all ground condition).

Classifies soil into digging scales as follows:

• E = Easy Digging; Loose Free Running Soils (like sands, fine gravels)
• M = Medium Digging; Denser Cohesive Soils (like clayey gravel, low Plasticity Index clays)
• M to H = Medium to Hard Digging; Like broken rock, wet heavy clay, gravel with boulders
• H = Hard Digging; Material requiring blasting and hard high Plasticity Index (PI) clays

3. The Trafficability
The trafficability upon soil as follows:

• Sands and Gravels – Free draining (flows well) and tends to have few problems.
• High Plasticity Index (PI) of Clays – Low permeability will prevent water ingress so the surface becomes dangerous but not in the long term.
• Silts or Low Plasticity Index of Clays – These cause the most problems as the permeability allows ingress which softens the soils thus weakening them.

The Excavation Works Safety while Handling Construction Equipments

Safety in excavation works while handling new or used construction machinery should be done carefully with proper planning. The location of underground utilities and other hazards should be determined before starting an excavation work. This should be upon the supervision of Electrical or Mechanical staff (among the Civil Teams), especially the site history is unknown.

Advice for handling excavation works at the designated area:

• The sides of excavation must be properly shored or sloped to the angle of repose (self supporting angle) to prevent cave-ins.
• The shoring must be provided if depth of excavation is over 1.2 m for better ground stability.
• When workers are required to enter a trench excavation of 1.2 m or more in depth a safe mean of egress such as stairway, ladder, or ramp must be provided for safer exit.

Try to avoid the operation of equipment near the top edge of an excavation because this increases the chance of slope failure. The collaboration with the Geologist is needed if working at the higher ground like hills, highlands or even mountains.

Advice for handling excavation works at higher ground:

• There should be no material deposited within 1.5 m of the trench edge.
• Ensure that workers are not allowed under loads being handled by excavators or hoist.
• Watch out for buried lines and containers when excavating in progress. The possible hazards may include: Toxic and flammable gases, electricity lines, and collapse of side slope caused by sudden release of liquids.
• Try to organize for daily inspection of excavations by a competent person to ensure safe workplace for both workers and construction machinery.
• Fence barriers build around all excavations area over 2 m deep.

Construction Machinery for Compaction Works and as the Transporter

In road construction, especially embankment fills where filling of suitable soil involved the compaction upon the layers of filled materials is very crucial. The soil is compacted to the standard degree of compaction (90% to 95%). The purpose of doing so is to increase density of soil, increasing bearing capacity of soil, to reduce soil compressibility, reducing water penetration, and the possibility of soil erosion. The compactor machine is the best for the job. Movement and transferring of material around, within the building site, or to another site or location also becomes the task of these heavy machines. Transportation of materials such as soil for filled materials, concrete for structures concreting, and for stock pile materials (aggregates, cements, reinforcement bars, and etc.) ought to be planned properly. Construction machinery that normally used is the lorries and trucks, dumpers, mixer trucks, forklifts, and mobile cranes.