Wednesday, May 6, 2020

Concrete Work for Blue Mountains Project †MyAssignmenthelp.com

Question: Discuss about the Concrete Work for Blue Mountains Project. Answer: Manage Project Quality Good quality concrete work is very essential for all construction works. Therefore the need to implement strategies that will ensure high quality concrete work in this project is inevitable. This quality manual will ensure that all concrete work for Blue Mountains Project meets the required standards specified in the contract documents and that of engineering practice. Formwork Formwork determines the final shape and position of concrete(Civil Guides, 2017). The design, preparation, installation and removal of formwork shall be done in accordance with AS 3610 and AS/NZS 4671 requirements and specifications. The formwork used in this project shall be strong and rigid enough to resist different loads imposed on it until when the concrete attains full strength(Committee BD-043, 2010). The formwork shall be designed correctly and installed properly; it shall be perfectly watertight so as to prevent water loss from fresh concrete after placing it in the formwork; internal surfaces of the formwork shall be cleaned and oiled before the concrete is placed in it; and concrete shall be dropped into the formwork vertically to prevent segregation. Materials The formwork in this project shall be made using timber, plastic, plywood and/or metal (aluminium or steel) depending on availability and cost. These materials shall be obtained from reputable suppliers. Samples shall be taken and tested to ensure that they meet the minimum strength requirements. Design and preparation Formwork shall be designed to fit the exact dimensions of concrete structures to be constructed. Engineers shall design the formwork sheeting, formwork bearers and formwork ties in accordance with AS 3610 requirements. Preparation shall include cutting the formwork into the desired shapes and sizes, cleaning and oiling internal surfaces of the formwork, and joining the forms so as to create the desired molds. Installation After preparation, the formwork shall be installed by qualified personnel in their respective locations. Appropriate tools and equipment shall be used to install the formwork to ensure that it is sufficiently braced and spliced to avoid misalignment. Levels and squares shall be used to ensure that the formwork is vertically and horizontally straight or aligned. The formwork shall also be maintained within specified design tolerances(Rodriguez, 2016). Removal Removal of formwork shall be after the specified period in the contract documents. The formwork shall only be removed after the concrete has gained sufficient strength. Removal of formwork shall be in the following sequence: shuttering that form vertical faces of columns, beams and walls; shuttering that form slab soffits; and shuttering that form beam soffits(Daily Civil, 2017). It is understood that inappropriate removal of formwork causes deformation of fresh concrete under its weight resulting to cracking, dimensional tolerance loss or collapse hence the formwork shall be removed by following the recommended procedure in AS 3610. Reinforcement Materials This projects shall use steel reinforcement. The reinforcement materials shall be obtained from reputable manufacturers and suppliers in the region. The company shall test the reinforcement to ensure that it has the desired properties. Design Engineers and designers shall design reinforcement accordingly to ensure that it is of the right type, size, shape and number as per the contract documents. Some of the key design elements to be considered include: bar spacing, bar supports and tying requirements(Concrete Reinforcing Steel Institute, 2018). Installation The reinforcement shall be installed as shown on the structural drawings. The key elements that shall be considered when installing reinforcement are: concrete cover, positioning and tolerances. These elements affect the final strength of concrete structure. Concrete All concrete works in this project will be done in accordance with the guidelines and requirements provided in AS 3600:2009 Concrete Structures(SAI Global, 2009). The main problems that occur in concrete trade are those associated with the quality of materials used, proportion of concrete mix, mixing method, transportation and placing, curing and tests(Twitty, 2008). These problems will be prevented from occurring in this project by applying the following techniques: Materials All materials (cement, aggregates (coarse and fine), water and admixtures (if any) used to make concrete shall be of high quality. The materials will sourced from reputable and certified suppliers in the region. The company shall send her representatives to various sources or suppliers so as to inspect how the materials are obtained, processed and prepared. The relevant physical, chemical and mechanical properties of the materials shall also be tested to ensure that they meet the required Australian building and engineering standards. These properties are the ones that determine the final strength of concrete(Biswas, 2013). Concrete mix design The ratio of concrete ingredients determines the strength of concrete(Ahmad Alghamdi, 2014). Proportions of concrete ingredients shall be designed by civil engineers so as to get the right mix for the job. The ratio of cement, aggregates and water shall be carefully determined for each concrete work so as to achieve the required strength of the structure. Before designing the concrete mix, the engineers will first establish the project specifications in contract documents. These specifications will act as guidelines on the proportions of the concrete ingredients. Measuring and mixing Batching in this project shall be done by volume. Gauge boxes shall be prepared and used to batch the concrete materials so as to attain the designed mix proportions. The company is aware that weight batching is more accurate than volume batching but the former is difficult to operate and more expensive than the later. After batching, the ingredients shall be mixed thoroughly to ensure that the concrete is uniform and attains the required quality. The mixing method that shall be used in this project is drum mixing, which is one of the most common and effective methods of concrete mixing. The concrete mixing machines shall be operated by qualified personnel. Mixing of concrete in this project shall be done by following the requirements of AS 1379. Handling and placing The concrete in this project shall be prepared on site hence it will only be transported over a short distance. Once the concrete is prepared, it will be placed before it hardens. Placing of concrete shall be done carefully by pouring the concrete in the prepared formwork in a manner that will prevent segregation. The concrete will be poured directly (using buckets and wheelbarrows) or by pump (using special concrete pumps), depending on the specific work being done. Vibrators will be used to enhance setting (where necessary) and the concrete will also be compacted and consolidated appropriately to eliminate air and other voids and also to ensure that the concrete is distributed to all parts of the formwork. Finishing Durability, smoothness and appearance of concrete surfaces are very important(Infrastructure Technology Institute, (n.d.)). To achieve this, concrete surfaces will be treated after consolidation so as to attain the expected properties. This will be done using different methods including: screeding, floating and trowelling, mechanical finishing (roughening the surface so as to make it less slick), use of concrete dyes, surface molding and polishing. The finishing shall be done in accordance with AS 3610. Curing After placing and consolidating the concrete, it will be cured properly and adequately for the recommended period in the contract documents (at least 7 days). During curing period, the concrete will be saturated fully with water. Nevertheless, the curing can be done by misting or sprinkling water on the concrete surface(Consumers Builders Supply Co., (n.d.)). This will help the concrete to develop the desired properties by developing full strength and preventing development of internal stresses. Damp fabric or plastic will be used to cover the concrete so as to avert evaporation and keep the concrete hydrated. Formwork will remain in place throughout the curing period. Testing Multiple samples of concrete shall be obtained and tested so as to determine if the concrete meets the desired properties. The concrete shall be sampled and tested in accordance with AS 1012(Main Roads Western Australia, 2011). The tests shall be carried out on both fresh and hardened concrete. These tests will include: compacting factor test, slump test, compression test, flexural strength test and tensile strength test. After 28 days, concrete is expected to have attained its maximum characteristic strength. If any of the samples fail, appropriate corrective actions shall be taken immediately. Generally In case non-conformance is identified, corrective actions shall be taken immediately depending on the stage of the work. If non-conformance is identified at the source of materials, the company will choose another supplier. Different records will also be maintained including sources of materials, test results of various materials, quality control and assurance reports, inspection reports, etc. The company shall ensure that each stage of the project is done by qualified personnel. Adequate tools and equipment shall also be provided to enable completion of the works. To ensure high quality work, the company shall have a quality control team that will be responsible for checking and ensuring that all works meet the required quality standards. The team will work independently and in collaboration with the client representatives. Environmental impacts and safety are other aspects that shall be considered at every stage of concrete work. In general, quality shall not be compromised at any cost or time and quality control of materials and workmanship shall be taken with the seriousness it deserves. The company shall also ensure that there is effective communication and collaboration with the client and her representatives to update them about quality control of concrete works. References Ahmad, S. Alghamdi, S., 2014. A Statistical Approach to Optimizing Concrete Mixture Design. The Scientific World Journal, Volume 2014, pp. 1-7. Biswas, L., 2013. Concrete Ingredients. [Online] Available at: https://www.acivilengineer.com/2013/05/concrete-ingredients.html [Accessed 11 February 2018]. Civil Guides, 2017. Mixing Concrete. [Online] Available at: https://civilguides.com/mixing-concrete/ [Accessed 10 February 2018]. Committee BD-043, 2010. Formwork for Concrete, Sydney, NSW: Council of Standards Australia. Concrete Reinforcing Steel Institute, 2018. Reinforcing Bar Placing. [Online] Available at: https://www.crsi.org/index.cfm/concrete/placing [Accessed 11 February 2018]. Consumers Builders Supply Co., (n.d.). Step by Step Guide to Completing Your Own Concrete Project. [Online] Available at: https://consumersbuilderssupply.com/?page_id=76 [Accessed 10 February 2018]. Daily Civil, 2017. Method and Period of Removing Formwork. [Online] Available at: https://www.dailycivil.com/method-period-removing-formwork/ [Accessed 11 February 2018]. Infrastructure Technology Institute, (n.d.). The Concrete Construction Process. [Online] Available at: https://iti.northwestern.edu/cement/monograph/Monograph2_3.html [Accessed 10 February 2018]. Main Roads Western Australia, 2011. Specification 901 Concrete - General Works, Sydney: MainRoads estern Australia. Rodriguez, J., 2016. Formwork Guidelines: Safety, Installation and Removal. [Online] Available at: https://www.thebalance.com/safety-installation-and-removal-of-formwork-844783 [Accessed 11 February 2018]. SAI Global, 2009. AS 3600-2009 Concrete Structures. Sydney, NSW: Standards Australia International Ltd. Twitty, W., 2008. Quality Management System for Ready Mixed Concrete Companies, Silver Spring, MD: RMC Research Education Foundation.

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