16 research outputs found
Oman Construction Industry Prospective on Cause of Construction Material Waste
Construction industry is second largest industry in gulf countries, that continuously rapidly growing. Similar to other countries around the world, construction industries in gulf region also facing problems due to oil industry uncertainties. Construction industry of gulf countries, construction material waste is getting higher concern. This paper aims to identify various factors in construction management causing construction material waste at Muscat, and Nizwa cities in Oman. Seventy-one (71) factors were collected from literature around the world and organized in structured questionnaire distributed amongst the construction experts focusing clients, consultants and contractors involved in the construction projects. The questionnaire was designed in such a way to collect construction waste causing factors in five major categories in (Design, Handling, Workers, Management, Procurement, and Site conditions). The collected data were analyzed by using Average Index method for each factor. Furthermore, construction material waste causing factors analyzed by individual response of client, consultant and contractor prospective. Analysis identified that ‘frequent design changes’; ‘wrong material storage’; ‘worker’s mistakes during construction’; ‘poor supervision’; ‘mistakes in quantity surveys’; and ‘poor site conditions’; are highest significant causes in each category respectively. The result of this study is useful to create or/and improve guideline considering waste generated from construction industry, to avoid problems in looming construction. It is concluded that the government organizations or/and construction industry itself can develop or improve legislation for avoiding construction material waste
Study on the Analytical Behaviour of Concrete Structure Against Local Impact of Hard Missile
Concrete is basic construction material used for almost all kind of structure. However, in the majority essential structures such as nuclear plants, Power plants, Weapon Industries, weapons storage places, water retaining structures like dams, highways barriers, bridges, & etc., concrete structures have to be designed as self-protective structure which can afford any disaster or consciously engendered unpleasant incidents such as incident occurs in nuclear plants, incident in any essential industry, terrorist attack, Natural disasters like tsunami and etc missile attack, and local impact damage generated by kinetic missiles dynamic loading (steel rods, steel pipes, turbine blades, etc.). This paper inquisitively is paying attention on verdict of the recent development in formulating analytical behavior of concrete and reinforced concrete structures against local impact effect generated by hard missile with and without the influence of dimensional analysis based on dominant non-dimensional parameters, various nose shape factors at normal and certain inclined oblique angles. The paper comprises the analytical models and methods for predicting penetration, and perforation of concrete and reinforced concrete. The fallout conquer from this study can be used for making design counsel and design procedures for seminal the dynamic retort of the concrete targets to foil local impact damage
Identification of Delay Factor in Oman Construction Industry
Construction industry is second most significant and largest industry in gulf countries that continuously and rapidly growing. However the decline in economies of gulf countries due to fluctuated oil has ambiguous effect on the construction industry. Like other countries around the world, construction industries in gulf region also facing many problems and amongst the most common problem is delay/time overrun. This paper aims to identify various factors in construction management which causing delay in construction projects at Muscat, Khabourah, Bidbid, Musanah and Sohar cities in OMAN. Fourty eight (48) delay factors identified from literature around the world and organized in structured questionnaire survey form. Delay factors were categorized into five major groups in construction process which are Planning, Design, Construction, Finishing, and Miscellaneous. The forms were distributed amongst the construction experts focusing clients, consultants and contractors involved in the construction projects. A total of 105 collected data were analyzed by using Average Index method for each factor. Furthermore, delay causing factors analyzed by individual response of client, consultant and contractor prospective. The analysis identified that ‘changes in scope of project’, ‘lack of communication between parties’, ‘shortage of skilled labour’, ‘mistakes during construction’, and ‘insufficient data collection and survey before designing’; are the most significant causes in each category respectively. The result of this study is useful to create or/and improve guideline considering delay, to avoid problems in looming construction
Development of a feature-based open soft-CNC system
Modern computer numerical control (CNC) is intended to be more flexible, interoperable, adoptable, open, and intelligent. In realisation of such a CNC system, an ISO standard known as STEP for numeric control (STEP-NC) or ISO 14649 was developed in 2004 to alleviate a number of challenges associated with the widely used CNC standard (ISO 6983). Implementation of STEP-NC was initially carried out on some commercial CNC systems via an indirect STEP-NC programming approach. However, this approach failed to meet all the requirements of a modern CNC system, due to the translation of data from the high level to low level, which is vendor-specific and machine tool dependent, thus detrimental to the basic resource independent philosophy of STEP-NC. This paper presents a new generation of CNC systems, based on the Open Architecture Control (OAC) technology supported by STEP-NC data model to fundamentally solve these challenges. The developed system employs a new set of techniques for STEP-NC data interpretation, graphical verification, execution, monitoring, and report generation that supersede the exiting techniques in scope and capability. Using these techniques, the proposed system provides a flexible, intelligent, and adaptable manufacturing platform that can provide unprecedented levels of scalability and resource allocation agility in modern manufacturing enterprises. A prototype implementation of the proposed model is based on STEP-NC interpretation, 3D simulation, machine motion control, and live video monitoring with automatic document generation modules has been used to verify and validate the system in conjunction with industrially inspired test components
Full hazards of smoking and benefits of stopping for women
Modern computer numerical control (CNC) is intended to be more flexible, interoperable, adoptable, open, and intelligent. In realisation of such a CNC system, an ISO standard known as STEP for numeric control (STEP-NC) or ISO 14649 was developed in 2004 to alleviate a number of challenges associated with the widely used CNC standard (ISO 6983). Implementation of STEP-NC was initially carried out on some commercial CNC systems via an indirect STEP-NC programming approach. However, this approach failed to meet all the requirements of a modern CNC system, due to the translation of data from the high level to low level, which is vendor-specific and machine tool dependent, thus detrimental to the basic resource independent philosophy of STEP-NC. This paper presents a new generation of CNC systems, based on the Open Architecture Control (OAC) technology supported by STEP-NC data model to fundamentally solve these challenges. The developed system employs a new set of techniques for STEP-NC data interpretation, graphical verification, execution, monitoring, and report generation that supersede the exiting techniques in scope and capability. Using these techniques, the proposed system provides a flexible, intelligent, and adaptable manufacturing platform that can provide unprecedented levels of scalability and resource allocation agility in modern manufacturing enterprises. A prototype implementation of the proposed model is based on STEP-NC interpretation, 3D simulation, machine motion control, and live video monitoring with automatic document generation modules has been used to verify and validate the system in conjunction with industrially inspired test components
Substantial Factors of Construction Management Causes Budget Overrun in Construction Industry of Oman
A Machine Learning Model for the Prediction of Concrete Penetration by the Ogive Nose Rigid Projectile
In recent years, research interest has been revolutionized to predict the rigid projectile penetration depth in concrete. The concrete penetration predictions persist, unsettled, due to the complexity of phenomena and the continuous development of revolutionized statistical techniques, such as machine learning, neural networks, and deep learning. This research aims to develop a new model to predict the penetration depth of the ogive nose rigid projectile into concrete blocks using machine learning. Genetic coding is used in Python programming to discover the underlying mathematical relationship from the experimental data in its non-dimensional form. A populace of erratic formulations signifies the rapport amid dependent parameters, such as the impact factor (I), the geometry function of the projectile (N), the empirical constant for concrete strength (S), the slenderness of the projectile (λ), and their independent objective variable, X/d, where X is the penetration depth of the projectile and d is the diameter of the projectile. Four genetic operations were used, including the crossover, sub-tree transfiguration, hoist transfiguration, and point transfiguration operations on supervised test datasets, which were divided into three categories, namely, narrow penetration (X/d < 0.5), intermediate penetration (0.5 ≤ X/d < 5.0), and deep penetration (X/d ≥ 5.0). The proposed model shows a significant relationship with all data in the category for medium penetration, where R2 = 0.88, and R2 = 0.96 for deep penetration. Furthermore, the proposed model predictions are also compared with the most commonly used NDRC and Li and Chen models. The outcome of this research shows that the proposed model predicts the penetration depth precisely, compared to the NDRC and Li and Chen models
A Systematic Review of the Concrete Durability Incorporating Recycled Glass
This systematic literature review (SLR) aims to present and analyze the recent research on the effect of recycled glass (RG) on the durability of concrete applications in terms of transport properties, chemical attack, alkali-silica reaction (ASR), and freeze/thaw (FT). RG could be utilized in concrete as a replacement or addition in three forms, namely glass powder (GP), glass aggregate (GA), and glass fiber (GF). The methodology of this study was based on a criterion for the selection process of reviewed studies to assess and synthesize the knowledge of the durability of RG in concrete. The articles were assessed and screened, then 114 review articles were selected. The direction of utilization of RG in concrete depends on the type, particle size, and pozzolanic performance. The valorization of RG had a positive impact on the durability of concrete; however, the mutual synergy of multiple substitutions with glass also had better results. Nowadays, fine glass aggregate (FGA) could be promoted to be used as a partial substitute for sand due to the easiness of recycling. Furthermore, GF is strongly encouraged to be used in fiber concrete. An analytical framework that highlights
the durability improvement of glass-modified concrete is presented. The results suggested that it is technically feasible to utilize glass as a part of concrete in the production of durable concrete. It provides a higher resistance to transport properties and chemical attacks by providing an extended lifespan. In addition, RG plays a great role in FT action in cold climates while it does not have a significant impact on ASR, provided refinement of glass results in the reduction of ASR and thus overcomes the expansion and cracks of concrete. However, up to 20% GP and up to 30% fine glass aggregate (FGA) could be replaced with cement and aggregate, respectively, to achieve a positive effect on durability based on the W/C ratio provided, not compromising the strength
Evaluation of Fresh and Hardened Concrete Properties Incorporating Glass Waste as Partial Replacement of Fine Aggregate
To date, the utilization of glass waste as an alternative aggregate in concrete has gained significantly increasing attention, owing to its remarkable properties. However, its high replacement content and glass particle size, of greater than 5 mm, causes an increase in the alkali-silica reaction expansion and a reduction in the concrete strength in most of the present literature. Therefore, this study investigated the effect of a lower sand replacement content (5–25%) in glass waste (smaller than 5 mm) on both the mechanical and durability properties of concrete. In particular, the effect of varying the replacement of fine aggregate by glass waste (5%, 10%, 15%, 20% and 25%) on compressive strength and water permeability of concrete (30 MPa grade) was evaluated at 7 and 28 days. Moreover, scanning electron microscope (SEM) tests were taken into account to assess the morphology characteristics of the concrete. Based on the results, the highest concrete strength (37.5 MPa) was recorded when the replacement percentage was 15%, while the control strength was 33.5 Mpa. The outcomes also exposed that the water permeability coefficient of the samples was decreased (0.883 × 10−9 m/s), at 5% compared to that of the control mix (1.097 × 10−9 m/s). In conclusion, a lower replacement percentage of glass waste leads to enhanced concrete properties and would act as a sustainable and alternative material in the near future
Evaluation of Fresh and Hardened Concrete Properties Incorporating Glass Waste as Partial Replacement of Fine Aggregate
To date, the utilization of glass waste as an alternative aggregate in concrete has gained significantly increasing attention, owing to its remarkable properties. However, its high replacement content and glass particle size, of greater than 5 mm, causes an increase in the alkali-silica reaction expansion and a reduction in the concrete strength in most of the present literature. Therefore, this study investigated the effect of a lower sand replacement content (5–25%) in glass waste (smaller than 5 mm) on both the mechanical and durability properties of concrete. In particular, the effect of varying the replacement of fine aggregate by glass waste (5%, 10%, 15%, 20% and 25%) on compressive strength and water permeability of concrete (30 MPa grade) was evaluated at 7 and 28 days. Moreover, scanning electron microscope (SEM) tests were taken into account to assess the morphology characteristics of the concrete. Based on the results, the highest concrete strength (37.5 MPa) was recorded when the replacement percentage was 15%, while the control strength was 33.5 Mpa. The outcomes also exposed that the water permeability coefficient of the samples was decreased (0.883 × 10−9 m/s), at 5% compared to that of the control mix (1.097 × 10−9 m/s). In conclusion, a lower replacement percentage of glass waste leads to enhanced concrete properties and would act as a sustainable and alternative material in the near future