Study on Techniques for Rapidly Testing the Composition of Concrete Mixture

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.

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The Effect of the Morphology of Coarse Aggregate on the Properties of Self-Compacting High-Performance Fibre-Reinforced Concrete

Materials ◽

10.3390/ma11081372 ◽

2018 ◽

Vol 11 (8) ◽

pp. 1372 ◽

Cited By ~ 21

Author(s):

Krzysztof Ostrowski ◽

Łukasz Sadowski ◽

Damian Stefaniuk ◽

Daniel Wałach ◽

Tomasz Gawenda ◽

...

Keyword(s):

Reinforced Concrete ◽

High Performance ◽

Coarse Aggregate ◽

Fresh Concrete ◽

Physical And Mechanical Properties ◽

Concrete Mixture ◽

Rheological Parameters ◽

Transverse Strain ◽

Fibre Reinforced Concrete ◽

High Performance Fibre

When understanding the effect of the morphology of coarse aggregate on the properties of a fresh concrete mixture, the strength and deformability of self-compacting high-performance fibre-reinforced concrete (SCHPFRC) can be seen to be critical for its performance. In this research, regular and irregular grains were separated from granite coarse aggregate. The morphology of these grains was described while using digital image analysis. As a result, the aspect ratio, roundness and area ratio were determined in order to better understand this phenomenon. Then, the principal rheological, physical, and mechanical properties of SCHPFRC were determined. The obtained results indicated that the morphology of the grains of coarse aggregate has an impact on the strength and stiffness properties of SCHPFRC. Moreover, significant differences in the transverse strain of concretes were observed. The morphology of the coarse aggregate also has an impact on the rheological parameters of a fresh concrete mixture. To better understand this phenomenon, the hypothesized mechanism of the formation of SCHPFRC caused by different morphology of coarse aggregate was proposed at the end of the article.

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Testing and Green Assessment Technology for Ready-Mixed Concrete

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.768.306 ◽

2018 ◽

Vol 768 ◽

pp. 306-313 ◽

Cited By ~ 1

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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Causes and Solutions for the Common Problems in Rotary Drilling Cast-in-Place Pile Construction

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.580-583.2249 ◽

2014 ◽

Vol 580-583 ◽

pp. 2249-2252 ◽

Cited By ~ 1

Author(s):

Zhao Yin Zhou ◽

Chang You Zhang

Keyword(s):

Quality Control ◽

Great Difficulty ◽

Rotary Drilling ◽

Quality Problem ◽

The Common ◽

Common Problems

Quality control in the rotary drilling cast-in-place pile construction is of great difficulty. Once a quality problem occurs, it would have an impact on the quality of the whole project. The text mainly analyzes the causes for the common problems in rotary drilling cast-in-place pile onstruction and gives some corresponding measures to solve them combined with engineering cases.

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Probability-based durability design and performance-based concrete quality control of a concrete harbor structure

Life-Cycle Civil Engineering ◽

10.1201/9780203885307.pt5 ◽

2008 ◽

pp. 691-696

Author(s):

O Gj√∏rv ◽

V √Örskog

Keyword(s):

Quality Control ◽

Durability Design ◽

Concrete Quality ◽

And Performance

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

Journal of Science and Technology in Civil Engineering (STCE) - NUCE ◽

10.31814/stce.nuce2020-14(2)-07 ◽

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.

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MAIN PROBLEMS OF MANUFACTURING ASPHALT CONCRETE MIXTURES IN LITHUANIA/ASFALTBETONIO MIŠINIŲ GAMYBOS SVARBIAUSIOS PROBLEMOS LIETUVOJE

Journal of Civil Engineering and Management ◽

10.3846/13921525.2000.10531562 ◽

2000 ◽

Vol 6 (1) ◽

pp. 39-45

Author(s):

Donatas Čygas

Keyword(s):

Asphalt Concrete ◽

High Speed ◽

Statistical Data ◽

Concrete Mixture ◽

Cement Material ◽

Asphalt Cement ◽

Concrete Mixtures ◽

Concrete Quality ◽

Regressive Analysis ◽

Speed Gradient

The article describes the main problems of manufacturing asphalt concrete mixtures at the factories under Ministry of Communication in the Republic of Lithuania. The Lithuanian Road Network is up to 21.122 km of state roads. 1.455 km of them are motorways, 3.415 km—national roads and 16.251 km—regional roads. Half of the state roads in Lithuania are paved with asphalt concrete. 98% of the motorways and 36% of the regional roads have asphalt pavement. Asphalt concrete pavement resistance to corrosion can be increased by improving asphalt concrete mixture production technology: ie by updating technological equipment, changing technological conditions and developing new methods of asphalt concrete mixture production. Therefore, the updating of asphalt concrete mixture production technologies is a very important factor for improving road operating properties and ensuring proper duration of asphalt concrete pavements. Here is the essence of the new separate successive technology: crushed stone and sand are mixed with bitumen in the main asphalt concrete mixer, the amount of bitumen being calculated according to the bitumen absorption in the materials. Then the asphalt cement material produced in a separate high-speed mixer is passed, and the whole mixture is remixed in the main mixer and supplied to the customer. Both separate consequent technologies differ from each other in the order of supplying asphalt cement material into the main mixing unit. Separate successive technology was theoretically grounded by the correlation between the technological thickness of bituminous film and the chemical-mineralogical composition and size of constituents, by the correlation between the particle size and their capability to compose aggregates, by the emergence of the oriented binding material coating on the technological bituminous film encoating mineral particles. Special attention is given to the manufacturing of asphalt cement material in a separate high-speed mixer (3 Table). It was theoretically grounded that mineral filler passing through the intensive shift zone between the paddle ends of the high-speed mixer and the walls of mixing chamber disintegrate and new active surfaces become visible. The molecular structure changes and free radicals appear. This intensive mixing guarantees high bitumen adsorption on the surface of mineral filler, which increases asphalt concrete resistance to corrosion and its durability, improves ecological environment in the asphalt concrete plant. In order to confirm the reliability of research results and explain correlative and regressive regularity, statistical data were processed applying statistical data processing programming system “STATGRAPHICS”. The linear regressive analysis for determining close relations of separate asphalt concrete quality indicators with speed gradient of asphalt cement material shift in a high-speed mixer was performed. Therefore, the possibility to change shift speed gradient from 3000 to 5000 1/s is provided in terms of reference for manufacturing asphalt concrete mixing plant. Correlation between separate asphalt concrete quality indicators and asphalt cement material shift speed gradient as well as bitumen amount in the asphalt cement material was determined by multi-dimensional regressive analysis of experimental data. The calculated correlation factor squared (R2) and F criteria indicate the adequacy and reliability of the multidimensional regression model.

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An updated and quality controlled surface mass balance dataset for Antarctica

The Cryosphere Discussions ◽

10.5194/tcd-6-3667-2012 ◽

2012 ◽

Vol 6 (5) ◽

pp. 3667-3702 ◽

Cited By ~ 1

Author(s):

V. Favier ◽

C. Agosta ◽

S. Parouty ◽

G. Durand ◽

G. Delaygue ◽

...

Keyword(s):

Quality Control ◽

Mass Balance ◽

Measurement Accuracy ◽

Field Measurements ◽

Spatial Density ◽

Surface Mass Balance ◽

West Antarctica ◽

Surface Mass ◽

Data Gaps ◽

The Antarctic

Abstract. We present an updated and quality controlled surface mass balance (SMB) database for the Antarctic ice sheet. We retrieved a total of 5284 SMB data documented with important meta-data, to which a filter was applied to discard data with limited spatial and temporal representativeness, too small measurement accuracy, or lack of quality control. A total of 3438 reliable data was obtained, which is about four times more than by applying the same data filtering process to previously available databases. New important data with high spatial resolution are now available over long traverses, and at low elevation in some areas. However, the quality control led to a considerable reduction in the spatial density of data in several regions, particularly over West Antarctica. Over interior plateaus, where the SMB is low, the spatial density of measurements remained high. This quality controlled dataset was compared to results from ERA-Interim reanalysis to assess model representativeness over Antarctica, and also to identify large areas where data gaps impede model validation. Except for very few areas (e.g. Adelie Land), the elevation range between 200 m and 1000 m a.s.l. is not correctly sampled in the field, and measurements do not allow a thorough validation of models in regions with complex topography, where the highest scattering of SMB values is reported. Clearly, increasing the spatial density of field measurements at low elevations, in the Antarctic Peninsula and in West Antarctica remains a scientific priority.

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