scholarly journals Determining the quantity of access tubes for quality control of bored pile concrete based on probability approach

2020 ◽  
Vol 14 (2) ◽  
pp. 76-86
Author(s):  
Bach Duong
Keyword(s):  
Quality Control ◽  
National Standard ◽  
Construction Process ◽  
Construction Stage ◽  
Probability Approach ◽  
Bored Pile ◽  
Defects Inspection ◽  
Concrete Quality ◽  
Bored Piles ◽  
Sonic Logging

Unexpected defects of concrete in a completed bored pile can arise during the construction stage. Therefore, post-construction testing of bored pile concrete is an important part of the design and construction process. The Cross-hole Sonic Logging (CSL) method has been the most widely used to examine the concrete quality. This method requires some access tubes pre-installed inside bored piles prior to concreting; the required quantity of access tubes has been pointed out in few literatures and also ruled in the national standard of Vietnam (TCVN 9395:2012). However, theoretical bases aiming to decide the required quantity of access tubes have not been given yet. A probability approach is proposed in this paper aiming to determine the essential quantity of access tubes, which depend not only on pile diameters, magnitude of defects, but also on the technical characteristics of CSL equipment. Keywords: access tubes; bored piles; CSL method; defects; inspection probability.

scholarly journals Accuracy and precision of the CSLT measurement system: An experiment to defect diagnoses in bored piles

2021 ◽  
Vol 28 (4) ◽  
pp. 176-185
Author(s):  
Zezhong Wang ◽  
Eric Tak Cho Ho ◽  
Inez Maria Zwetsloot
Keyword(s):  
Hong Kong ◽  
Measurement System ◽  
Measurement Accuracy ◽  
Large Diameter ◽  
Housing Projects ◽  
Bored Pile ◽  
Accuracy And Precision ◽  
Bored Piles ◽  
Pile Type ◽  
Sonic Logging

A new measurement system called Crosshole Sonic Logging Tomography (CSLT) provides information on the size, shape, and orientation of defects in a bored pile. The CSLT measurement system has not (yet) been accredited in Hong Kong for foundation testing. Bored piles in Hong Kong are generally wide and deep. Existing measurement accuracy studies do not consider this large type of bored piles. The objective of this research is to quantify the measurement accuracy and precision of the CSLT method for large diameter bored piles (the most common pile type for public housing projects in Hong Kong). A test pile was constructed with known defects and perform experiments with a CSLT measurement system to quantify its accuracy and precision. CSLT is found to be accurate in detecting shape, size, and location of large defects but small defects close to the tube are difficult to detect. Generally speaking, CSLT has satisfactory accuracy and precision for practical use. The use of CSLT can be considered as a feasible method in defect diagnosis of bore piles in Hong Kong.

scholarly journals Implementation of Techniques and its Management on Constructional Activities

2019 ◽  
Vol 8 (9S2) ◽  
pp. 454-458
Keyword(s):  
Quality Control ◽  
Net Present Value ◽  
Payback Period ◽  
Construction Process ◽  
Present Value ◽  
Effective Technique ◽  
In Situ Method ◽  
Concrete Quality ◽  
Precast Construction

Precast construction is a time effective technique which consumes less time than cast-in-situ technique for execution. Savings of time in construction would compensate the overall profit for the owner. Precast technology achieves better concrete quality control with less wastage of materials. In this paper, G+3 commercial multi-storied building is planned and compared with the precast construction and cast-in-situ construction for cost analysis using Payback Period Method and Net Present Value Method. Scheduling is done using Primavera. Primavera (P6) turn out to be competent tool in monitoring, scheduling, controlling and updating the project at any stage of construction process. Through payback period it is able to deduce that, the initial investment can be recovered approximately one month before the cast-in-situ method when we are employing precast approach. Also, considering investment criteria i.e. Net present value method shows that, a higher profit is obtained towards the investment in precast than in cast-in-situ method. Hence, precast construction method proves to be profitable when compared to conventional method of construction.

Construction Technology and Quality Control Measures of Bored Pile

2011 ◽  
Vol 94-96 ◽  
pp. 1946-1950
Author(s):  
Ming Hua Hu ◽  
Lian Sheng Gu ◽  
Di Lian Tang
Keyword(s):  
Quality Control ◽  
Pile Foundation ◽  
Control Measures ◽  
Construction Technology ◽  
Bored Pile ◽  
Bored Piles

Filling pile is a common form of pile foundation work, it passes the superstructure loads to the deep stabilitily soil or rock , reducing the non-uniform settlement of ground and foundation. Because of bored piles is done underground, underwater, quality control is difficult. The construction technology and quality control measures of bored pile is been introduced.

scholarly journals Potential and prospects of photocatalytic disinfection: using sustainable solarenergy- driven photocatalysts

2021 ◽  
Vol 28 (4) ◽  
pp. 165-175
Author(s):  
Juhua He ◽  
Kenny W K Hui ◽  
Irene M C Lo
Keyword(s):  
Hong Kong ◽  
Measurement System ◽  
Measurement Accuracy ◽  
Large Diameter ◽  
Housing Projects ◽  
Bored Pile ◽  
Accuracy And Precision ◽  
Bored Piles ◽  
Pile Type ◽  
Sonic Logging

A new measurement system called Crosshole Sonic Logging Tomography (CSLT) provides information on the size, shape, and orientation of defects in a bored pile. The CSLT measurement system has not (yet) been accredited in Hong Kong for foundation testing. Bored piles in Hong Kong are generally wide and deep. Existing measurement accuracy studies do not consider this large type of bored piles. The objective of this research is to quantify the measurement accuracy and precision of the CSLT method for large diameter bored piles (the most common pile type for public housing projects in Hong Kong). A test pile was constructed with known defects and perform experiments with a CSLT measurement system to quantify its accuracy and precision. CSLT is found to be accurate in detecting shape, size, and location of large defects but small defects close to the tube are difficult to detect. Generally speaking, CSLT has satisfactory accuracy and precision for practical use. The use of CSLT can be considered as a feasible method in defect diagnosis of bore piles in Hong Kong.

Development and Application of Quality Control System for Highway Subgrade Construction

2019 ◽  
Vol 2 (5) ◽  
Author(s):  
Tong Wang
Keyword(s):  
Quality Control ◽  
Real Time ◽  
Detection Method ◽  
System Development ◽  
Effective Control ◽  
Construction Process ◽  
Development Mode ◽  
The Road ◽  
Whole Process

The compaction quality of the subgrade is directly related to the service life of the road. Effective control of the subgrade construction process is the key to ensuring the compaction quality of the subgrade. Therefore, real-time, comprehensive, rapid and accurate prediction of construction compaction quality through informatization detection method is an important guarantee for speeding up construction progress and ensuring subgrade compaction quality. Based on the function of the system, this paper puts forward the principle of system development and the development mode used in system development, and displays the development system in real-time to achieve the whole process control of subgrade construction quality.

Study on Techniques for Rapidly Testing the Composition of Concrete Mixture

2013 ◽  
Vol 838-841 ◽  
pp. 30-35
Author(s):  
Xiao Bin Sun ◽  
Tian Ling Du ◽  
Bo Tian
Keyword(s):  
Quality Control ◽  
Laboratory Test ◽  
Rapid Detection ◽  
Measurement Accuracy ◽  
Fresh Concrete ◽  
Concrete Mixture ◽  
Quality Problem ◽  
Detection Techniques ◽  
Concrete Quality ◽  
Practical Engineering

With regards to the quality problem of concrete that cant be found out earlier in the quality control, this paper discussed the principle to rapidly detect composition of concrete mixture and analyzed the measurement accuracy of water checker for fresh concrete through laboratory test. Experiments showed that the error in unit cement and unit water measured by instruments is relatively small and able to meet the accuracy requirements. And, the application of rapid detection techniques to the concrete quality control in practical engineering has achieved good results.

PROJECT DEVELOPMENT OF THE NATIONAL STANDARD ON QUALITY CONTROL AND IDENTIFICATION OF THE CHEWING TOBACCO

2019 ◽  
Author(s):  
Н.П. САМОЙЛЕНКО ◽  
И.Г. КАНДАШКИНА ◽  
Е.В. ГНУЧИХ ◽  
Л.А. МИРНЫХ
Keyword(s):  
Quality Control ◽  
Smokeless Tobacco ◽  
Fractional Composition ◽  
National Standard ◽  
Tobacco Products ◽  
Chewing Tobacco ◽  
Smokeless Tobacco Products ◽  
Technical Specifications ◽  
First Time ◽  
General Technical

Рассмотрены идентификационные признаки некурительных табачных изделий табака жевательного и снюса. Разработан метод определения фракционного состава табака жевательного. На основании научных исследований впервые разработан проект национального стандарта ГОСТ Р Табак жевательный. Общие технические условия, который после утверждения и введения в действие будет использоваться для идентификации этого вида некурительной табачной продукции. The identification signs of smokeless tobacco products: of chewing tobacco and snus are considered. A method for determining the fractional composition of chewing tobacco has been developed. On the basis of scientific research for the first time developed a draft national standard GOST R Chewing tobacco. General technical specifications. After approval and entry into force, this standard will be used to identify types of smokeless tobacco products.

Testing and Green Assessment Technology for Ready-Mixed Concrete

2018 ◽  
Vol 768 ◽  
pp. 306-313 ◽  
Author(s):  
Chun Zhi Zhao ◽  
Yi Liu ◽  
Shi Wei Ren ◽  
Jiang Quan
Keyword(s):  
Quality Control ◽  
Energy Conservation ◽  
Building Material ◽  
Rapid Development ◽  
Green Building ◽  
Process Quality ◽  
Concrete Quality ◽  
Assessment Technology ◽  
Ready Mixed Concrete ◽  
Mixed Concrete

Concrete is the most extensively used material in building and civil project structure. With the rapid development of economic construction, urban construction and infrastructure construction increase year by year, so there is a greater demand for concrete, which brings the rapid development of ready-mixed concrete industry. During the rapid development, structural safety and durability problems caused by concrete quality appear frequently. Meanwhile, to implement the fundamental national policies of resource conservation and environment protection, according to Green Building Action Plan (GUOBANFA [2013] No.1) approved by CPC Central Committee and the State Council, besides meeting the quality requirements, ready-mixed concrete must also meet the green products requirements of "energy conservation, emission reduction, safety, convenience and recyclability" for the vigorous development of green building material and supporting the requirements for building energy conservation, green building and new-type urbanization construction. By quality testing, this paper elaborates the green assessment technology for ready-mixed concrete in combination with raw material quality control, design of mix ratio, production process quality control, construction process quality control, residual concrete treatment, hardened concrete quality control, and control of dust, noise and wastewater. The greening of ready-mixed concrete brings the production and application of green building material, promotes the transformation and upgrading of building material industry and drives the development of green building.

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