Types of Constructions

Construction is any process that leads to a completion of structures. It has many types such as heavy or civil construction, building construction and industrial construction.

Under the field of civil engineering and architecture, construction is a method that consists of assembling or building infrastructure. Usually, this work is managed by a project manager and supervised by a construction engineer, construction manager, project architect or design engineer. There are several types of construction projects such as industrial construction, building construction and heavy or civil construction.

Building construction is a process of adding small or big structures to land or real property. Most of the building construction jobs are small reconstructions like adding bathroom or reconstruction of a room. Often times, the titleholder of the property acts as a designer, paymaster and laborer for the entire job. However, all the building construction jobs include several elements in legal consideration, financial and usual design.

Building constructions are procured publicly or privately using different delivery methodologies such as management contracting, hard bid, construction management at risk, design & build bridging, and negotiated price.

Residential construction technologies, resources and practices should conform to the codes of practice and local building authority regulations. The materials used are widely accessible in the market. The common materials used are timber, stone and brick. The cost of construction is on a “per square foot” basis. This is since homes can vary significantly on local site considerations, conditions, and economies of scale.

Heavy or civil construction is a procedure of adding infrastructure to the environment of a building. The builders are usually government agencies both at the local or national level. These also have legal and financial considerations. This project primarily serves the public interest. They are undertaken and supervised by some large private corporations such as power companies, golf courses and whoever oversees the construction of access dams, roads and railroads.

Industrial construction requires highly specialized skill in construction, planning and design. Holders of this project are normally industrial, for profit or large corporations. This corporation can be found in industries such as chemical, medicine, power generation and petroleum manufacturing.

There are many reputable construction companies in the US. The Turner Construction Company is one of the most commendable. It works with a number of national sector groups that concentrate on a usual building type. Their famous clients include Biotechnology, Pharmaceutical, Justice, Healthcare and Breen Building as well as Aviation, Sports and Public Assembly. Turner Construction Company also offers additional services of supply chain management, Turner Logistics, TCS or Turner Casualty and Surety that provides loss control programs and proactive safety. It is one of the largest construction running companies in the US.

Another company is Anderson Construction Group. It provides professional builds or designs, general contracting, wind mitigation, SoftPlan construction documents and construction managements. This company delivers a large variety of industrial, residential, medical, industrial, and specialty services and projects. It is one of the leaders in providing value added construction services to their consumers by making a successful partnership with them during the construction processes.

IHC Construction Company is another trusted US construction company. It manufactures concrete blocks packed by hydraulic pressure. IHC Construction Company has construction management, pre-construction, underground contractors and horizontal drilling. The horizontal drilling of IHC is the future of underground conduit and pipe construction. It eliminates or reduces damages caused by the usual open cut trenching methods. The Design & Build division of the company offers construction services to offices, residential warehouses, industrial and commercial markets.

Soil Classification

Geotechnical engineers classify the soil particle types by performing tests on disturbed (dried, passed through sieves, and remolded) samples of the soil. This provides information about the characteristics of the soil grains themselves. It should be noted that classification of the types of grains present in a soil does not account for important effects of the structure or fabric of the soil, terms that describe compactness of the particles and patterns in the arrangement of particles in a load carrying framework as well as the pore size and pore fluid distributions.

Classification of soil grains

In the US and other countries, the Unified Soil Classification System (USCS)is often used for soil classification. Other classification systems include the British Standard BS5390 and the AASHTO soil classification system^.

Classification of sands and gravels

In the USCS, gravels (given the symbol G) and sands (given the symbol S) are classified according to their grain size distribution. For the USCS, gravels may be given the classification symbol GW (well-graded gravel), GP (poorly graded gravel), GM (gravel with a large amount of silt), or GC (gravel with a large amount of clay). Likewise sands may be classified as being SW, SP, SM or SC. Sands and gravels with a small but non-negligible amount of fines (5 % - 12 %) may be given a dual classification such as SW-SC.

Atterberg Limits

Clays and Silts, often called 'fine-grained soils', are classified according to their Atterberg limits; the most commonly used Atterberg limits are the Liquid limit (denoted by LL or w_l), Plastic Limit (denoted by PL or w_p), and Shrinkage limit (denoted by SL). The shrinkage limit corresponds to a water content below which the soil will not shrink as it dries.
The liquid limit and plastic limit are arbitrary limits determined by tradition and convention. The liquid limit is determined by measuring the water content for which a groove closes after 25 blows in a standard test Alternatively, a fall cone test apparatus may be use to measure the liquid Limit. The undrained shear strength of remolded soil at the liquid limit is approximately 2 kPa. The plastic limit is the water content below which it is not possible to roll by hand the soil into 3 mm diameter cylinders. The soil cracks or breaks up as it is rolled down to this diameter. Remolded soil at the plastic limit is quite stiff, having an undrained shear strength of the order of about 200 kPa
The Plasticity index of a particular soil specimen is defined as the difference between the Liquid limit and the Plastic limit of the specimen; it is an indicator of how much water the soil particles in the specimen can absorb. The plasticity index is the difference in water contents between states when the soil is relatively soft and the soil is relatively brittle when molded by hand.

Classification of silts and clays

According to the Unified Soil Classification System (USCS), silts and clays are classified by plotting the values of their plasticity index and liquid limit on a plasticity chart. The A-Line on the chart separates clays (given the USCS symbol C) from silts (given the symbol M). LL=50% separates high plasticity soils (given the modifier symbol H) from low plasticity soils (given the modifier symbol L). A soil that plots above the A-line and has LL>50% would, for example, be classified as CH. Other possible classifications of silts and clays are ML, CL and MH. If the Atterberg limits plot in the"hatched" region on the graph near the origin, the soils are given the dual classification 'CL-ML'.

Indices related to soil strength

Liquidity Index

The effects of the water content on the strength of saturated remolded soils can be quantified by the use of the liquidity index, LI:

When the LI is 1, remolded soil is at the liquid limit and it has an undrained shear strength of about 2 kPa. When the soil is at the plastic limit, the LI is 0 and the undrained shear strength is about 200 kPa

Relative density

The density of sands (cohesionless soils) is often characterized by the relative density, D_r

where: e_max is the "maximum void ratio" corresponding to a very loose state, e_min is the "minimum void ratio" corresponding to a very dense state and e is the in situ void ratio. Methods used to calculate relative density are defined in ASTM D4254-00(2006)
Thus if D_r = 100% the sand or gravel is very dense, and if D_r = 0% the soil is extremely loose and unstable.

Types of Concrete Admixtures

Chemical concrete admixtures are material in the form of powder or fluids that are added to concrete to give it certain characteristics not obtainable with plain concrete mixes. In normal use, admixture dosages are less than 5% by mass of cement and are added to the the concrete at the time of batching/mixing. The most common types of concrete admixtures are:
1. Accelerators speed up the hydration (hardening) of the concrete.

2. Retarders slow the hydration (hardening) of the concrete, and are used in large or difficult pours where partial setting before the pour is complete is undesirable.

3. Air-entrainers add and distribute tiny air bubbles in the concrete, which will reduce damage during freeze-thaw cycles thereby increase the concrete’s durability.

4. Plasticizers (water-reducing admixtures) increase the workability of plastic of fresh concrete, allowing it be placed more easily with less consolidating effort.

5. Superplasticizers ( high-range water-reducing admixtures)are a class of plasticizers which have fewer deleterious effects when use to significantly increase workability. Alternatively; plasicizers can be used to reduce the water content of a concrete (and have been called water reducer due to this application) while maintaining workability. This improves its strength and durability characteristics.

6. Pigments can be used to change the color of concrete, for aesthetics. Mainly they are ferrous oxides.

7. Corrosion inhibitors are used to minimize the corrosion of steel and steel bars in concrete.

8. Bonding agent are used to create a bond between old and new concrete.

9. Pumping aids improve pumpability, thicken the paste and reduce dewatering of the paste.

Thus, chemical admixture is one ingredient creating concrete that provide the differentiation of concrete types.