Preparation and Application of High Dropping Non Vibration Self-Compacting Concrete

2014 ◽  
Vol 584-586 ◽  
pp. 1490-1494
Author(s):  
Shu Jin Li ◽  
Jian Fen Li ◽  
Hong Ping Qian

High dropping non vibration concrete is widely used in high-rise steel tube concrete construction. In this paper, a high dropping non vibration self-compacting concrete with high mobility, low slump loss, and good anti-segregation ability is developed by mixing addition of PCA superplasticizer and SCC composite expansive admixture. The test results showed that the admixture and cement used in the test possess sound compatibility. The slump flow of self-compacting concrete prepared are more than 660mm, T500 of 2.8~7.5s, 1h slump flow loss of less than 10%, and the segregation rate of less than 7.5%. Through strictly control production and dropping construction, supplemented by field ultrasonic detection measures, the high dropping self-compacting concrete in steel tube achieved successful application for a high-rise building.

2012 ◽  
Vol 170-173 ◽  
pp. 3266-3269
Author(s):  
Su Hua Yin ◽  
Ying Na Dong

Concrete filled steel tube is widely used in super high-rise steel structure, but there are many problem in the construction of concrete filled steel tube. With the construction of Wanxin building as an example, this paper described the selection of the construction program, and analyzed the disadvantages in construction such as the difficulties of concrete pumping and the problems of pipe blockage, pipe explosion and concrete curing during the process of construction. Based on structural characteristics and construction difficulties, the key technique of steel tube concrete construction are introduced in detail. It can provide significant reference and guide for super high-rise building construction.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Chaohua Jiang ◽  
Shanshan Huang ◽  
Yuwen Zhu ◽  
Yifeng Lin ◽  
Da Chen

The fresh, mechanical, and durability properties of the polypropylene fiber-reinforced mortar (PP FRM) and the basalt fiber-reinforced mortar (BFRM) with various fiber contents were tested in this paper. The test results show that the presence of polypropylene (PP) fiber and basalt fiber (BF) in the mortar reduces the initial slump flow and increases the slump flow loss rate. The bond strength and flexural strength of fiber-reinforced mortar (FRM) are improved, whereas no obvious improvement on the compressive strength has been observed. Compared with the control mortar, the bond strength of PP FRM and BFRM reinforced with 0.6 kg/m3, 1.6 kg/m3, and 2.6 kg/m3fiber increases by 16.60%–28.80% and 10.60%–21.40%, respectively. Furthermore, FRM shows lower drying shrinkage, superior abrasion resistance, water impermeability, and freeze-thaw resistance compared with the control mortar. The abrasion resistance strength of PP FRM and BFRM is 77.30% and 38.65% more than the control mortar with 2.6 kg/m3fiber content. Therefore, PP FRM and BFRM are suitable to be utilized as repair materials, especially in repairing hydraulic structures surfaces with excellent bond strength and abrasion resistance.


2019 ◽  
Vol 9 (6) ◽  
pp. 4901-4904
Author(s):  
A. Saand ◽  
K. A. Jamali ◽  
M. A. Keerio ◽  
T. Ali ◽  
N. Bhatti

This paper presents the fresh properties of Self-Compacting Concrete (SCC) containing metakaolin (MK) produced by calcination of the natural material soorh of district Thatta Sind in Pakistan. Five mixes were tested, including four MK mixes replacing 5-20% of cement, with 0.38 water/binder (W/B) ratio. The fresh properties of the SCCs were evaluated using slump flow, T50, V-funnel, J ring, L-box and sieve segregation tests. Compressive strength of the control and the MK SCC was also investigated. The fresh concrete test results revealed that SCC could be developed by substituting cement with local MK, using 2% superplasticizers and without using a viscosity-modifying amplifier. The SCC with 15% replacement of cement with local MK showed maximum compressive strength, which was 10.39% higher than the control specimen’s without MK.


2013 ◽  
Vol 706-708 ◽  
pp. 539-544
Author(s):  
Bo Yuan ◽  
Zhean Lu ◽  
Rui Xiong ◽  
Xiao Hui Yuan ◽  
Wei Guo Chen

In order to achieve the optimal interface composite properties between the inner wall of steel tube and the core concrete as well as evaluate the expansion properties of concrete filled steel tubular rationally, the mechanical properties of 5 CFST specimens were tested in this paper with different dosage of expanding agent measured from zero to 28d curing age. Besides, this research also examined the validity and accuracy of homemade concrete stress box. The result proved that the test results coincide with the calculated value of theoretical analysis perfectly, which provided experimental and theoretical basis for the expansion mechanism of self-stressing concrete in steel tube constraint and the designing goals of expansion properties in concrete filled steel tubular.


2021 ◽  
Vol 6 (1) ◽  
pp. 32
Author(s):  
Abdul Karim Hadi ◽  
Sudarman Supardi ◽  
Mukti Maruddin ◽  
A.Alal Azhari Yusuf ◽  
Rahmat Hidayat Samsuddin

Dalam dunia konstruksi pekerjaan beton memegang peranan sangat penting, baik pada bangunan struktural maupun non struktural.Dapat dilihat bahwahampir setiap bangunan yang didirikanseperti perumahan, gedung bertingkat, jembatan, jalan,  bendungan dan saluran irigasi serta bangunan lainnya selalu  memerlukan adanya pekerjaan betonterutama pada pekerjaan konstruksi beton bertulang. Selama ini pemadatan atau vibrasi dilakukan tidak sesuai dengan prosedur dan dapat menurunkan kualitas beton. Salah satu solusi mengatasi masalah tersebut yaitu dengan penggunaan self compacting concrete.Tujuan penelitian ini untuk mengetahui pengaruh penambahan superplasticizerterhadap workabilitybeton self compacting concretedan untuk mengetahui pengaruh metode self compacting concreteterhadap sifat mekanis beton. Penelitian dilakukan di laboratorium struktur dan bahan dengan penggunaan superplasticizertype sika-viscocrete 3115N sebanyak 2% dari berat semen. Pembuatan job mix designdibuat dengan metode SNI. Berdasarkan hasil penelitian superplasticizerdapat meningkatkan workabilitypada beton segar. Hasil pengujian slump cone test pada beton normal sebesar 8 cm, sedangkan hasil slump flowpada beton self compacting concretesebesar 75 cm. Pada penelitian ini didapatkan nilai kuat tekan beton normal sebesar 25,096 Mpa dan nilai kuat tekan beton SCC sebesar 30,264 Mpa dari mutu rencana 25 Mpa dan nilai kuat tarik belah beton normal sebesar 2,343 Mpa atau 9,340% dari nilai kuat tekan dan nilai kuat tarik belah beton SCC sebesar 3,358 Mpa atau 11,09%  dari nilai kuat tekan. Berdasarkan data yang didapatkan self compacting concrete memilki workabilitydan sifat mekanis yang lebih baik.   In the world of construction, concrete work plays a very important role, both in structural and non-structural buildings. It can be seen that almost every building that is erected such as housing, high rise buildings, bridges, roads, dams and irrigation canals and other buildings always requires concrete work, especially in reinforced concrete construction work. During this time compaction or vibration is done not in accordance with procedures and can reduce the quality of concrete. One solution to overcome this problem is the use of self compacting concrete. The purpose of this study was to determine the effect of adding superplasticizer to the workability of self compacting concrete and to determine the effect of the self compacting concrete method on the mechanical properties of concrete. The research was carried out in the structure and material laboratory using 2% sika-viscocrete superplasticizer as much as 2% by weight of cement. Job mix design is made using SNI method. Based on the results of research superplasticizer can increase workability in fresh concrete. The slump cone test results on normal concrete are 8 cm, while the slump flow results on self-compacting concrete are 75 cm. In this study, the compressive strength value of normal concrete was 25.096 MPa and the compressive strength value of SCC concrete was 30.264 MPa from the quality plan of 25 MPa and the value of normal concrete split tensile strength was 2.334 MPa or 9.340% of the compressive strength and SCC concrete compressive strength value. 3.358 MPa or 11.09% of the compressive strength. Based on the data obtained, self compacting concrete has better workability and mechanical properties


2020 ◽  
pp. 136943322098166
Author(s):  
Shuhao Yin ◽  
Bin Rong ◽  
Lei Wang ◽  
Yiliang Sun ◽  
Wuchen Zhang ◽  
...  

This paper studies the shear performance of the connection with the external stiffening ring between the square steel tubular column and unequal-depth steel beams. Two specimens of interior column connections were tested under low cyclic loading. The deformation characteristics and failure modes exhibited by the test phenomena can be summarized as: (1) two specimens all exhibited shear deformation in steel tube web of the panel zone and (2) weld fracture in the panel zone and plastic hinge failure at beam end were observed. Besides, load-displacement behaviors and strain distributions have been also discussed. The nonlinear finite element models were developed to verify the test results. Comparative analyses of the bearing capacity, failure mode, and load-paths between the equal-depth and unequal-depth beam models have been carried out.


2021 ◽  
Vol 11 (8) ◽  
pp. 3315
Author(s):  
Fabio Rizzo

Experimental wind tunnel test results are affected by acquisition times because extreme pressure peak statistics depend on the length of acquisition records. This is also true for dynamic tests on aeroelastic models where the structural response of the scale model is affected by aerodynamic damping and by random vortex shedding. This paper investigates the acquisition time dependence of linear transformation through singular value decomposition (SVD) and its correlation with floor accelerometric signals acquired during wind tunnel aeroelastic testing of a scale model high-rise building. Particular attention was given to the variability of eigenvectors, singular values and the correlation coefficient for two wind angles and thirteen different wind velocities. The cumulative distribution function of empirical magnitudes was fitted with numerical cumulative density function (CDF). Kolmogorov–Smirnov test results are also discussed.


2015 ◽  
Vol 1119 ◽  
pp. 752-755
Author(s):  
Chang Zheng Sun ◽  
Zheng Wang

Optimization of mix proportion parameter ,Using ordinary raw materials makes a C80 high performance self-compacting concrete;By joining a homemade perceptual expansion agent, significantly improve the early strength of concrete and effective to solve the high strength of self-compacting concrete caused by gelled material consumption big contraction;Further study on the working performance of high-strength self-compacting concrete, age strength, analysis the influence factors of concrete are discussed.


2011 ◽  
Vol 243-249 ◽  
pp. 258-262
Author(s):  
Jun Chen ◽  
Jia Lv ◽  
Qi Lin Zhang ◽  
Zhi Xiong Tao ◽  
Jun Chen

Laminated glass has been increasing widely used in high rise buildings as a kind of safety glass in recent years. So we should analyze its material property. In this paper, we use flexural experiments and ANSYS program to analyze the main factors that affect the flexural capacity of the laminated glass. The test results show that the flexural capacity is closely related to film. And the ANSYS program had got good agreement with the experimental results. Comparison of experimental results with calculated ones indicates that the current design code will lead to conservative results and the equivalent thickness of laminated glasses provided in the code should be further discussed.


Author(s):  
Dorota Brzezinska ◽  
Marcin Fryda

The following technical note demonstrates full-scale staircase test results of the pressure differential system improvement method described by Fryda et al. in 2021. It is a continuation of experimental research on the impact of the escape route’s leakages on the pressure differential systems for staircases. Based on the lab experiments, it has been found that an additional throttle of the leak implemented in the pressure differential system improves its effectiveness and allows it to be more precisely adjusted to the required overpressure. The results presented in this article have confirmed this hypothesis and provided the opportunity to apply for new patent solutions of a special throttle of the leak control and pressure regulating system. The proposed new leakage-based improvements could increase the efficiency of existing systems based on proportional-integral-derivative controller and could also be installed in new buildings.


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