Construction and development loans are loan options that are made available to businesses when there is a need to construct a commercial property, but there will not be any income generated until after the property is completed and capable of production or retail activity that will generate revenue. It is possible to apply for loans of this type from many banks and other lending institutions. The duration of the loan may range anywhere from a few months to several years, depending on amount of time required to complete the construction and allow the business to begin selling goods and services as a source of income.

The use of a C&D, or construction and development, loans is often an excellent choice for newly formed business ventures. The delay in beginning the process of repaying the loan allows the business a chance to establish a physical presence and begin the process of offering goods and services for sale. Many construction and development loans contain a clause that allows the debtor to have a short grace period after the anticipated completion date of the physical facility. This grace period can help account for any short delays in the construction process, as well as allow the debtor to open the facility and have time to begin accumulating sales that in turn create revenue that can be used to pay off the loan.

Not only new businesses can make use of construction and development loans. Well-established companies often use this model as a means of opening new facilities in new locations, or to renovate or expand existing facilities. The structure of the loan is ideal, since it makes it possible to delay repayment until the facility is able to generate money on its own. This means that the business does not have to rely on income from its other facilities to carry the cost of the loan until construction is completed, and the new or refurbished facility is capable of engaging in productive efforts.

Because the facility under construction cannot reasonably be used as collateral for construction and development loans, banks and other lenders may approve the loan on some other basis. If the company owns other properties, these may be pledged as collateral. However, sometimes all that is required is a solid credit rating and a past history that assures the lender that the loan will be paid off according to terms.

A bank may offer what is know as a bridge loan, which is simply a construction and development loan of relatively short duration. The bridge loan may carry terms of several months, as in the case of expanding or adapting an existing property, or be written for three or so years when the construction involves the creation of a brand new building or series of buildings. As with all types of loans, any individual or business applying for one or more construction and development loans will need to comply with applicable national banking regulations and also meet the standards set by the individual lending institution.

ASTM International, originally known as the American Society for Testing and Materials, is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services. The organization’s headquarters is in West Conshohocken, Pennsylvania, about 5 miles northwest of Philadelphia.

ASTM predates other standards organizations such as BSI (1901), DIN (1917) and AFNOR (1926), but differs from these in that it is not a national standards body, that role being taken in the USA by ANSI. However, ASTM has a dominant role among standards developers in the USA, and claims to be the world’s largest developer of standards. Using a consensus process, ASTM supports thousands of volunteer technical committees, which draw their members from around the world and collectively develop and maintain more than 12,000 standards.

ASTM International publishes the Annual Book of ASTM Standards each year in print, CD and online versions. The online version was available by subscription and cost was based upon usage. For 2008, the complete set of books or CDs cost almost USD $9000 and included 81 volumes.

ASTM standards

The standards produced by ASTM International fall into six categories:

* the Standard Specification, that defines the requirements to be satisfied by subject of the standard.
* the Standard Test Method, that defines the way a test is performed. The result of the test may be used to assess compliance with a Specification.
* the Standard Practice, that defines a sequence of operations that, unlike a test, does not produce a result.
* the Standard Guide, that provides an organized collection of information or series of options that does not recommend a specific course of action.
* the Standard Classification, that provides an arrangement or division of materials, products, systems, or services into groups based on similar characteristics such as origin, composition, properties, or use.
* the Terminology Standard, that provides agreed definitions of terms used in the other standards.

The quality of the standards is such that they are frequently used worldwide.

The Annual Book of ASTM Standards covers 15 sections of interest plus a master index:

1. Iron and Steel Products
2. Nonferrous Metal Products
3. Metals Test Methods and Analytical Procedures
4. Construction
5. Petroleum Products, Lubricants, and Fossil Fuels
6. Paints, Related Coatings, and Aromatics
7. Textiles
8. Plastics
9. Rubber
10. Electrical Insulation and Electronics
11. Water and Environmental Technology
12. Nuclear, Solar, and Geothermal Energy
13. Medical Devices and Services
14. General Methods and Instrumentation
15. General Products, Chemical Specialties, and End Use Products
16. Index to all sections and volumes

ASTM Standards can be purchased as a digital library subscription or individually from qualified standards providers. When maintaining a large standards library, sometimes it is best to purchase a digital subscription to stay current on standards and in compliance with all copyright laws.

Four collections are now available via a dynamic, online portal. EHS Professionals can procure licenses to a Biodiesel portal (which includes the latest ASTM D6751-08 standard), Due Diligence aka Vapor Intrusion portal, Department of Transportation portal, or a Custom Collection portal that can be purchased by section and/or volume across disciplines or the entire compilation in its entirety.

Construction cost constitutes only a fraction, though a substantial fraction, of the total project cost. However, it is the part of the cost under the control of the construction project manager. The required levels of accuracy of construction cost estimates vary at different stages of project development, ranging from ball park figures in the early stage to fairly reliable figures for budget control prior to construction. Since design decisions made at the beginning stage of a project life cycle are more tentative than those made at a later stage, the cost estimates made at the earlier stage are expected to be less accurate. Generally, the accuracy of a cost estimate will reflect the information available at the time of estimation.

Construction cost estimates may be viewed from different perspectives because of different institutional requirements. In spite of the many types of cost estimates used at different stages of a project, cost estimates can best be classified into three major categories according to their functions. A construction cost estimate serves one of the three basic functions: design, bid and control. For establishing the financing of a project, either a design estimate or a bid estimate is used.

1. Design Estimates

For the owner or its designated design professionals, the types of cost estimates encountered run parallel with the planning and design as follows:

* Screening estimates (or order of magnitude estimates)
* Preliminary estimates (or conceptual estimates)
* Detailed estimates (or definitive estimates)
* Engineer’s estimates based on plans and specifications

For each of these different estimates, the amount of design information available typically increases.

2. Bid Estimates

For the contractor, a bid estimate submitted to the owner either for competitive bidding or negotiation consists of direct construction cost including field supervision, plus a markup to cover general overhead and profits. The direct cost of construction for bid estimates is usually derived from a combination of the following approaches.
* Subcontractor quotations
* Quantity takeoffs
* Construction procedures.

3. Control Estimates

For monitoring the project during construction, a control estimate is derived from available information to establish:
* Budget estimate for financing
* Budgeted cost after contracting but prior to construction
* Estimated cost to completion during the progress of construction.

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The Foundations for Risk Management presented herein will be the basis for the tools and other content that the Risk Management Program committee will deliver at the upcoming convocation. These Foundations were developed by engineers in private practice to help engineering firms focus their practice on avoiding and minimizing risk.
The first five Foundations deal with the process of the engineering business and the last five deal with project management.

1. Culture

Create a culture of managing risk and preventing claims
Creating a culture of risk management and claims prevention entails instilling in your company an overriding vision that stresses quality control and managing risk as a vital part of your business practice.
This vision must become a core value of the firm and come from the top down. Stress the importance of risk management as often as possible among the staff, as well as the consequences of ignoring it. Creating this culture requires both strategic and operational planning. It should involve all levels of the staff and even involve clients. Quality must take precedence over profits. When quality is established, profits tend to follow.

2. Prevention and Proactivity

Act with preventive techniques, not just react
Develop processes and systems within the firm with risk prevention in mind. Often, early planning canidentify potential sources of risk, and early intervention can mitigate the severity of claims. When risk is identified, a proactive plan can be developed to change the conditions that lead to that risk or avoid the risk altogether. Clearly, some events happen without warning and we must react. Although we cannot plan for the specifics of each case, identifying where risks may arise and establishing priorities before hand provide the proper framework with which to deal with unforeseen events. Having a plan allows quick action to minimize the damage these events may cause. An example of this would be having a plan in place to deal with an owner who wants to drive down your fee by asking to eliminate construction phase services. Do you have a plan that will allow you to promptly respond to such a request in a way that minimizes your
risk?

3. Planning

Plan to be claims free
Closely related to the Foundation of Prevention and Proactivity is the attribute of planning. Claims-free results do not happen by chance; they require proper planning. Strategic planning means taking into consideration how items such as staff hiring and retention, client selection, project type selection, training programs and quality assurance programs can all contribute to reducing claims. Project planning is also an important aspect of risk management. A project work plan can help focus on areas that reduce risk such as information flow, communication pathways, contract negotiations, and scope definition. For a plan to be effective, it should be simple, workable, and readily communicable. Communicating the plan to all involved parties, reinforcing the need to adhere to it, and monitoring activities to see if it is being followed are all important steps to having an effective, claims-free practice.

4. Communication

Communicate to match expectations with perceptions
It is well documented that communication issues represent a large percentage of the basis for claims against engineers. When all parties in a project communicate their expectations and perceptions early and often, the “disconnects” between opposing parties can be readily established. Steps can then be taken to resolve those differences and align everyone’s expectations and perceptions. To be effective, communication must flow both up and down the chain of command so that all parties are informed. Good planning will lead to good communication. All parties should agree on acceptable means and lines of communication early in the process. Develop tools to aid the communication process such as correspondence logs, telephone conversation logs, and e-mail protocol.
Communication must be handled in a professional and courteous manner. When dealing with a contentious issue, it is not a good practice to send a letter or e-mail immediately after composing it. Take time and then re-read the communication before sending it. Communicating only the facts of the case and avoiding emotional outbursts or statements of opinion can help to avoid problems or making problems worse.

5. Education

Educate all of the players
Proper training is the basis for expecting proper results in any field. Engineers that have a greater amount of experience have a duty to pass their wisdom on to both staff and clients. As professionals, engineerspossess a unique body of knowledge that our clients rely on to accomplish their goals. Creating a formal mentoring process helps less-experienced staff members become more effective in their careers. The skills that experienced engineering professionals gain during their careers relating to business practices such as negotiating, communicating, and planning are all factors that can aid in managing risk. Those skills must be passed down to less-experienced employees so that everyone can effectively participate in risk management. Owners who are unfamiliar with the design and construction process also need to be educated so that expectations about the nature of professional services and the proper allocation of risk can be cast.

6. Scope

Develop and manage a clearly defined scope of services
A well-defined and written scope of work serves several purposes. First, it helps avoid misunderstandings by clearly defining which parties will be responsible for completing which task and when those tasks will be completed. Second, it establishes the basis for negotiations regarding compensation. Third, it draws the line that forms the basis for additional services. Last, it serves as a starting point for preparing a work plan. Communicate the agreed-upon services to the entire staff so that they can recognize when a request for services goes beyond the contracted scope. Obligations can be extended simply by the actions of employees. If they begin to perform services that are not within the original scope — without first receiving an agreement for extra compensation it will be very difficult, after the fact, to explain that those services were not in the original scope. Be especially careful while making site visits that the engineer’s actions do not extend the firm’s obligations to include responsibility for job-site safety or directing the work of the contractor. Extending the scope simply increases the amount of risk one is taking without appropriate compensation.

7. Compensation

Prepare and negotiate fees that allow for quality and profit
Whether effort-based or value-based criteria are used for establishing fees, always keep in mind that sufficient fees will allow for sufficient time to prepare quality work. Always negotiate the compensation along with a scope of services so that the owner knows exactly what is included in the paid fee. By being transparent with the client regarding the basis of the fee proposal, a basis for the amount of contingency can be established. This will help avoid arguments over extra service requests later. When negotiating fees, have in mind a number below which the firm will not take the project. Be ready to walk away from a client with whom you have historically lost money, or from a project type that poses too much risk compared to the reward being offered.

8. Contracts

Negotiate clear and fair agreements
A good contract that is fair to all parties can minimize the risk that an engineer faces during the course of a project. On the other hand, a poorly worded contract can greatly increase that risk. Review each contract or obtain legal aid to detect and delete or modify risk-enhancing language. A good approach is to use contracts that have been prepared by organizations representing designers, such as the CASE contracts, as a starting point for negotiations. Always be sure that the terms of the contract are insurable under the firm’s professional liability insurance. For example, most insurance policies do not provide for the defense of an indemnitee, even though that term is often found in indemnity agreements. A good contract will recognize that professional services are being provided — not a product — and therefore perfection cannot be warranted by the service provider. The principle that risk should be fairly proportioned to the parties based on the benefit that each party is receiving is what forms the basis for a good contract. On that basis, the engineer should be held responsible for his own negligent errors or omissions, but not for the errors of other parties.

9. Contract Documents

Produce quality contract documents
For most engineering work, the final deliverable is the document that will direct the construction of theproject. The first step to produce quality documents is to have a plan to do so. Plan the work effort required in conjunction with the engineering and CAD technician staff. Have the client approve the written design criteria and then widely distributed it to everyone involved in the documents’ production. The more complex the design, the higher the risk involved in design and documentation. Make the client aware of this and engage the client in a discussion about simplifying the design or providing the engineer with a higher compensation to account for such complexity.
There are several suggestions to help improve the documentation quality. One of the best tools to help produce quality documents in a shorter time frame is the computer-aided design and drafting software that has become available in the past few years. It has greatly increased productivity and quality. Take advantage of it. Prepare job specifications during the design development phase in order to ensure the specifications and drawings are coordinated. Take advantage of repetition in design elements and use the knowledge of more experienced staff members to avoid spending wasted time “re-inventing the wheel.”

10. Construction Phase

Provide services to complete the risk management process
The final phase of a project, the construction phase, is also the time when many claims against the engineer arise. This is certainly not the time to let down your guard in protecting against risk. There are various tasks associated with the construction phase wherein the contractor responsible for construction and the engineer interact. There are submittals to be checked, requests for information to be answered, change orders to be evaluated, and site visits to be made. Each of these tasks should be performed in a timely and efficient manner so as to eliminate the engineer as the reason for a delay. A good practice to diffuse a claim of delay is to keep good records of the information flow between the contractor and the design team. Establish a non-adversarial relationship with the project superintendent so that you can work together as partners to achieve a common goal.

Ten Foundations for Risk Management – A conclusion

As implied in the title, Foundations for Risk Management, the issues raised in this paper should serve as a
starting point for all engineers in dealing with the issue of risk and how to avoid or mitigate it. By focusing on the suggestions made in each of the 10 areas of practice that are discussed, it is hoped that the engineering community can reach success as defined by the goal of zero liability claims. Begin laying your foundation for risk management by analyzing your current practices.

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Risks in construction projects may be classified in a number of ways. One form of risks classification is as follows:

1. Socioeconomic factors
   • Environmental protection
   • Public safety regulation
   • Economic instability
   • Exchange rate fluctuation
2. Organizational relationships
   • Contractual relations
   • Attitudes of participants
   • Communication
3. Technological problems
   • Design assumptions
   • Site conditions
   • Construction procedures
   • Construction occupational safety

The environmental protection movement has contributed to the uncertainty for construction because of the inability to know what will be required and how long it will take to obtain approval from the regulatory agencies. The requirements of continued re-evaluation of problems and the lack of definitive criteria which are practical have also resulted in added costs. Public safety regulations have similar effects, which have been most noticeable in the energy field involving nuclear power plants and coal mining. The situation has created constantly shifting guidelines for engineers, constructors and owners as projects move through the stages of planning to construction. These moving targets add a significant new dimension of uncertainty which can make it virtually impossible to schedule and complete work at budgeted cost. Economic conditions of the past decade have further reinforced the climate of uncertainty with high inflation and interest rates. The deregulation of financial institutions has also generated unanticipated problems related to the financing of construction.

Uncertainty stemming from regulatory agencies, environmental issues and financial aspects of construction should be at least mitigated or ideally eliminated. Owners are keenly interested in achieving some form of breakthrough that will lower the costs of projects and mitigate or eliminate lengthy delays. Such breakthroughs are seldom planned. Generally, they happen when the right conditions exist, such as when innovation is permitted or when a basis for incentive or reward exists. However, there is a long way to go before a true partnership of all parties involved can be forged.

During periods of economic expansion, major capital expenditures are made by industries and bid up the cost of construction. In order to control costs, some owners attempt to use fixed price contracts so that the risks of unforeseen contingencies related to an overheated economy are passed on to contractors. However, contractors will raise their prices to compensate for the additional risks.

The risks related to organizational relationships may appear to be unnecessary but are quite real. Strained relationships may develop between various organizations involved in the design/construct process. When problems occur, discussions often center on responsibilities rather than project needs at a time when the focus should be on solving the problems. Cooperation and communication between the parties are discouraged for fear of the effects of impending litigation. This barrier to communication results from the ill-conceived notion that uncertainties resulting from technological problems can be eliminated by appropriate contract terms. The net result has been an increase in the costs of constructed facilities.

The risks related to technological problems are familiar to the design/construct professions which have some degree of control over this category. However, because of rapid advances in new technologies which present new problems to designers and constructors, technological risk has become greater in many instances. Certain design assumptions which have served the professions well in the past may become obsolete in dealing with new types of facilities which may have greater complexity or scale or both. Site conditions, particularly subsurface conditions which always present some degree of uncertainty, can create an even greater degree of uncertainty for facilities with heretofore unknown characteristics during operation. Because construction procedures may not have been fully anticipated, the design may have to be modified after construction has begun. An example of facilities which have encountered such uncertainty is the nuclear power plant, and many owners, designers and contractors have suffered for undertaking such projects.

If each of the problems cited above can cause uncertainty, the combination of such problems is often regarded by all parties as being out of control and inherently risky. Thus, the issue of liability has taken on major proportions and has influenced the practices of engineers and constructors, who in turn have influenced the actions of the owners.

Many owners have begun to understand the problems of risks and are seeking to address some of these problems. For example, some owners are turning to those organizations that offer complete capabilities in planning, design, and construction, and tend to avoid breaking the project into major components to be undertaken individually by specialty participants. Proper coordination throughout the project duration and good organizational communication can avoid delays and costs resulting from fragmentation of services, even though the components from various services are eventually integrated.

Attitudes of cooperation can be readily applied to the private sector, but only in special circumstances can they be applied to the public sector. The ability to deal with complex issues is often precluded in the competitive bidding which is usually required in the public sector. The situation becomes more difficult with the proliferation of regulatory requirements and resulting delays in design and construction while awaiting approvals from government officials who do not participate in the risks of the project.

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Feasibility Study Request

The Project Proposal Template may be used to request funding to conduct a Feasibility Study, which in turn is used to provide an analysis of the objectives, requirements, and concepts of the proposed work, including justification, schedule, and deliverables. Its main purpose it to determine the technical and financial viability of a proposed change as well as to assist in identifying or clarifying activities, cost, timeframes and/or requirements (system and/or business). During the analysis, the objectives of the proposed work are defined based on the needs identified.

Depending on the project, the Feasibility Study may be Stage 1 of a large project. The Feasibility Study may also be used to conduct a preliminary part of project where it is unclear how to quantify the resources or if the product/system/process to be implemented needs to be identified before progressing to complete a Project Proposal.

The outcomes of the study must be considered and planned for. This means that the Feasibility Study Report requirements should be kept in mind at all times during the Planning Phase and throughout the life of the study. The output from the Feasibility Study is a report detailing the methodology used, the evaluation criteria, the study findings and recommendations.

Once the study is completed a Feasibility Study Report is required as the outcome for the work undertaken. If the study recommends continuing with the project idea then a Project Proposal for a new project should be completed and submitted either with the Feasibility Study Report or soon after.

Feasibility Study Report

The Feasibility Study Report template is used to provide information about the outcomes and success of a feasibility study. The report should include details on methodology used, the evaluation criteria, options analysed with findings and recommendations resulting from the study. Supporting documentation may be included as appendices.

The report recommendations may support proceeding with a project or project stage as a result of the study. In this case the Project Proposal should be prepared. Both documents should be submitted to the governing authorities for approval.

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In order to achieve accurate estimates in Project Management, cost estimating strategy is a must.

This cost estimating strategy is developed based on a three-step process. These steps lead to a more accurate cost estimate by incorporating the knowledge gained during the design phase of the project combined with knowledge from previous projects. With the adoption of this strategy, a strategy explanation should be included in the Project Management Plan.

Rough initial Estimates

The Initial Rough Estimate is developed during the Initiating Phase and is based on the information provided in the high-level scope along with information from previous projects the project manager has been involved with or from similar projects they have heard about. This Initial Rough Estimate will be presented as a part of the Concept Proposal.

Intermediate Estimates

During the Planning Phase, the project requirements will be developed by the analyst and the project manager for the customer’s review and approval and will further clarify and define the project estimates. More details are provided to the project team to allow them to help the project manager with project estimates. A detailed project schedule is created by the project manager to provide duration and effort for each task, the assignment of resources for each task, and a complete and detailed cost estimate of the project effort.

Final Detailed Project Estimate

The detailed project designs are created allowing the project manager to refine some of the project tasks and add the estimation of costs such as hardware, software, and items such as test equipment or additional space for the project team. At this point, the initial estimates created for the Concept Proposal can be updated or replaced to reconcile the more accurate total project cost information. The new estimate is communicated to the project stakeholders.

Shotcrete has been widely used for tunneling works and slope protection, it is also used for architectural purposes. There are two types of shotcrete application, the wet and dry process. Shotcrete is a concrete transported by means of air under pressure with high velocity. It is applied and compacted in the same time against a surface.

Shotcrete components

As mentioned earlier, shotcrete differ from normal concrete by the way to apply it.
Here below some points that should be observed and respected when producing shotcrete mixes.

Cement

It is obvious that the cement quality properties play a dominant role in the high early strength behaviour. The specific surface (Blaine value) should be not lower than 3500 cm2/g. Compressive strength of the cement lime should be more than 10 MPa after 2 days and more than 35 MPa after 28 days.
First stiffening of the cement lime should not be before 1,5 hours and not after 4 hours from the start of the mixing with water.
The choice of cement however is at all the time governed by the required properties of the hardened concrete and not for their suitability for spraying.
The early strength requirement would determine the cement content. Usually for dry process we dose 280-350 kg for 1 m3 of dry bulk mix. For wet process, cement content can vary from 425 kg/m3 to 500 kg/m3. Suitable cement content regarding the strength required can be verified only by shotcrte trial. A slight retardation of the setting time is observed by the tri-calcium aluminates in case of sulfate resistant cement. Blast furnace cements cause the same problem.

Water

All water use for mixing cementitious components must be clean as it occurs naturally. Spring, waste- water must be analyzed in order to determine their compatibility with the other components of the mix. The water cement ratio should not exceed 0,40 if high strength or durable shotcrete is required.

Sand

Sand must be clean. It is always combined with aggregate. The S/A ratio varies from 55% - 65%. Despite to specify the sand grading itself according to a certain grading refereeing to a certain standards, it is the combination of the sand and aggregate together that must comply with the standard used.

Aggregate

Aggregate would be mostly crushed aggregate considering that they could be produced from the excavated material. However we should avoid flaky elongated aggregate.

Sand / Aggregate ratio

This ratio must satisfy a few conditions. The S/A ratio must allow easy shotcrete pumping or rotor filling. As a rule it is clear that mixes containing fines in excess would cause dust, increase the water demand. A contrary, mixes containing aggregates in excess would increase rebound.
It has been observed that good pumping properties are achieved when the particles smaller than 1.18 mm represent around 40% of the sand / aggregate combination.

Superplasticiser / stabilizer:

They are taken in consideration for the production of wet mix only.
They are usually Naphthalene or polycarboxylate base superplasticiser.
Only some special modified Lignosulfate base superplasticiser could be used.
As normal concrete, their use allows a reduction of the water by still keeping suitable workability. However, it must be noted that lower the W/C is faster early strengths are reached. Dosage would depend on the workability required.
Usually they are dosed from 1,0-1,7 %.

Accelerator

They are definitely required for wet mix application. They are used in certain cases for dry process application too.
They are added for various reasons. They allow the spraying of thick layer when out-put is high and consequently the shotcrete reaching the substrate would not fall down. They allow developing early strength that would minimize surrounding rock deformations. They limit the rebound formation. Certain type of accelerators allows sealing work when substrate shows water leakage. They exist in powder or liquid form. They are either Alkali or Alkali Free. Typical dosages of modern accelerator are from 3-8% by weight of cement

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Introduction to shotcrete or sprayed concrete

Shotcrete or gunite was invented by Mr. Carl Ethan Akeley (1864-1926) in 1910. For attractions of a park, this American Architect was mandated to realize in concrete the reproduction of a dinosaur. Considering the sizes of the structure, he had the idea to develop a “cement gun” machine allowing the spraying of a cementitious mortar. Shotcrete was created!

Probably a symbolic coincidence, but the same year, Mr. Kaspar Winkler founded Sika. Since that time Sika has greatly contributed to the development of the shotcrete technology. By shotcrete technology development, we mean the continuous development of chemical additives and admixtures for shotcrete and as well the development of spraying equipments.

Fields of shotcrete application

Shotcrete is mainly used in Underground construction projects as preliminary or permanent structural support. By Underground constructions, we mean the construction of structures like road-rail tunnel, hydropower plant, mines, parking, subway, metro, storage area etc.
However shotcrete is as well as an economical tool to realize stabilization work (slope), swimming pools, waterways, concrete repairs, inner lining and architectural structures. About 90% of the shotcrete applied goes into Underground construction projects. Total volume of shotcrete worldwide applied yearly is more than 12 millions cubic meters

What is shotcrete?

As per the American Concrete Institute (ACI), shotcrete can be defined as a mortar or concrete, pneumatically projected at high velocity through a pressure resistant conveying line onto a surface, where it is compacted on impact.

Cement, sand, aggregate, water, additives and admixtures are the components entering in the production of the shotcrete mix.

Compared to normal concrete, shotcrete differs mainly from three points:

• The maximal size of the aggregate used.

• The way to place it.

• The mixture of shotcrete can be dry or wet.

Regarding terminology we can describe Gunite as sprayed mortar while Shotcrete as a sprayed concrete.
By gunite we means a cementitious mixture of which the particles size is limited to 8 mm.
For shotcrete we consider the use of aggregates of which the maximal size is 16 mm. However, in the last 10 years there is a tendency to limit the maximal aggregate size to 12 mm.

Shotcrete development can be summarized from its start to nowadays as follows:
Dry process –> dry process with powder accelerator –> wet process with Alkali liquid accelerator –> wet process with Alkali free accelerator.
(To be continued)

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Eurocode (also known as EN Eurocode or EC) is a set of pan-European model building codes developed by the European Committee for Standardisation.

The EN Eurocode is organised in 57 parts, each part published as a separate European Standard. By 2002, ten Eurocodes have been developed and published:

* EN 1990: (Eurocode 0 ) Basis of structural design
* EN 1991: (Eurocode 1 ) Actions on structures
* EN 1992: (Eurocode 2 ) Design of concrete structures
* EN 1993: (Eurocode 3 ) Design of steel structures
* EN 1994: (Eurocode 4 ) Design of composite steel and concrete structures
* EN 1995: (Eurocode 5 ) Design of timber structures
* EN 1996: (Eurocode 6 ) Design of masonry structures
* EN 1997: (Eurocode 7 ) Geotechnical design
* EN 1998: (Eurocode 8 ) Design of structures for earthquake resistance
* EN 1999: (Eurocode 9) Design of aluminium structures

The Eurocodes form a common European set of structural design codes for civil engineering work. They will eventually replace the national codes published by national standard bodies (e.g. BS 5950) after a period of co-existence. At the moment some Eurocodes are still in a trial phase, so they are characterised as ENV instead of EN until they are officially adopted. Additionally, each country may have a National Annex to the Eurocodes which will need referencing for a particular country (e.g. The UK National Annex).

As with other European standards, the Eurocodes will be used in public procurement specifications and to assess products for the CE mark.