The proto machine made sand is a new artificial material for environmental protection with grain size smaller than 5 mm made of water cleaned crushed stones or gravels broken and separated by
The test results showed that the flexural and compressive strengths of the machine made sand concrete were greater than the standard sand with the same stone powder content
ledge rock shall be given a crushed value of 100 percent iii Except for ledge rock any mineral aggregate having 10 percent or less passing a designated sieve before crushing and 90 percent or more passing the same sieve after crushing shall be given a crushed value of 100 percent [A] Final crushed aggregate is the product of only the
For example the annual consumption of manufactured sand in mainland China has increased from billion tons in 2008 to 19 billion tons in 2019 accounting for 90% of China s annual aggregate consumption At present machine made sand has become the mainstream material in the construction industry
The chloride ion diffusion coefficient CIDC is an important index to evaluate the durability performance of machined sand concrete In this study a database of CIDC is established for 82 sets of experimental data for 4 influence parameters Meanwhile different models with 4 input variables Water to binder ratio fly ash ratio relative humidity and
The slump values of the concrete made with different types of sands ranged between 28 to 30 mm to inch with same water to cement ratio This slump value was taken as constant for further compressive strength testing of hardened concrete 70 Gauhar Sabih et al / Procedia Engineering 145 2016 66 â 73
Based on appropriate assessment methods and indexes of self compacting concrete proposed properties of concrete made with river sand and machine made sand was firstly compared in different mix
Tests have shown that the mica content in the finished sand is greatly reduced after magnetic separation to remove mica It can be controlled within 2% which meets the sand standard and the concrete mixing performance produced by
Measured slump and unit weight ρ co of fresh concrete as well as compressive strength at 28 days f cu 28 are listed in Table cohesiveness of fresh concrete was improved with the increase of stone powder content where the slump expressed first increase and then decrease while stone powder content was 5 9% and 9 13%
Due to the type of aggregate formation quarry sand was found to acquire higher FAA values in comparison to the mining sand Wheel tracking test machine was used to measure rutting behavior on the asphalt mixture and it was conducted at 40 o C Fatigue beam test was performed to evaluate the fatigue behavior of the asphalt concrete mixes
Comparative experiments for the Bond work index value determination using the standard and quick procedures were carried out on samples of limestone and andesite and on composite samples
Traditional natural river sand is used as a fine aggregate for concrete but due to the severe environmental situation in recent years many places have asked for a ban or restriction on the extraction of river sand This has resulted in an increasing demand for concrete using machine made sand instead of natural sand The estimation and prediction of the
This paper studied the influence of various performance indexes of machine made sand on concrete work performance and admixture adaptability The experimental results show The MB value of machine
The working performance and durability of medium and low strength machine made sand concrete with different stone powder contents were studied and the optimal range of stone powder content in
Experimental study was carried out on the concrete mixed with machine made sand and recycled coarse aggregate MSRAC three strength grades of concrete were designed by changing the water to
Machine made sand instead of natural sand has become an inevitable choice for the sustainable development of the concrete industry The index value of fine aggregate roughness in group 12 is greater than that in group 11 and slightly less than that in group 3 Qiu T Impact and improvement of crushed tuff sand on sulfate resistance of
CEN Standard sand natural siliceous sand consisting mostly of rounded particles of silica content of at least 98% CEN means Committee for European Norms The CEN sand is standard sand used for preparation of mortars in the testing of hydraulic cements by European standard
The crushing index value of machine made sand with better particle shape is generally in the range of 20% to 25% The content of needle flakes in machine made sand is most sensitive to the crushing index value The crushing index value of machine made sand is generally above 30% or even higher
machine made sand to the cement concrete pavement Ke Guoju [8 9] et al researched on the wear resistance of machine made sand cement concrete Results show that the the wear resistance of machine made sand concrete is positively correlated with its strength which is related to the limit value
gravel/sand/clay mixtures SW Well graded sands gravelly sands little or no fines SP Poorly graded sands gravelly sands little or no fines SM Silty sands poorly graded sand/ silt mixtures SC Clay like sands poorly graded sand/clay mixtures ML Inorganic silts and very fine sands rock flour silty or clay like
In the current Chinese National Standard GB/T 14 684 2021 the methylene blue value is defined as an index used to determine the adsorption capacity of MS and mixed sand Methylene blue is a cationic dye that is easily soluble in water and appears blue in the aqueous solution
To check the influence of sand alternatives and blending ratios fresh and hardened state properties of alternative mortars were analyzed and compared with reference mortars which were made with river sand alone Wet and dry bulk densities of mortars were increased with lower replacement levels with offshore sand
The slump values of the concrete made with different types of sands ranged between 28 to 30 mm to inch with same water to cement ratio This slump value was taken as constant for further compressive strength testing of hardened concrete 70 Gauhar Sabih et al / Procedia Engineering 145 2016 66 â 73
Machine made sand The granite lithologic machine made sand produced by Shaanxi Dapu Construction Waste Resource Utilization Co Ltd is used as shown in Fig 2 The apparent density is 2721 kg/m 3 the bulk density is 1717 kg/m 3 and the content of particle size less than is % which is continuous Gradation