An experimental study and failure mechanism analysis on dynamic behaviors of plain concrete under biaxial compression-compression
12
Citation
23
Reference
10
Related Paper
Citation Trend
Abstract:
In order to explore the dynamic mechanical properties of concrete under biaxial compression-compression, a true triaxial instrument was used to conduct an experimental study on the dynamic mechanical properties of plain concrete under biaxial compression-compression. Eight different lateral compressive stresses (0 MPa~14 MPa) and four strain (10−5/s, 10−4/s, 10−3/s and 10−2/s) rate were considered. From this, the effects of lateral compressive stress and loading strain rate on the biaxial compression-compression properties of concrete were compared and analyzed by obtaining the failure modes, principal compressive stress-strain curves and related mechanical characteristic parameters of plain concrete under different loading conditions. The research results show that: with the increase of lateral compressive stress, the failure modes of concrete were developed from columnar failure at low lateral compressive stress to sheet-like failure at high lateral compressive stress. With the increase of lateral stress, the development trend of concrete failure mode decreased gradually under the influence of strain rate. With the increase of lateral compressive stress, the variation range of concrete principal compressive stress decreased first and then tended to be relatively stable under the influence of strain rate. With the increase of strain rate, the increase range of concrete principal compressive stress decreased under the influence of lateral compressive stress. The influence mechanism of lateral compressive stress and strain rate on biaxial compression-compression performance of concrete was analyzed. Meanwhile, based on Kupfer biaxial compression failure criterion, a biaxial compression dynamic failure criterion model considering the effect of loading strain rate on plain concrete was proposed. The research results provided an important theoretical basis for the application and development of concrete engineering.Rainwater was acidic water and had a pH generally ranging from pH 5.2 to 6.5. In this research using quantitative research types, where the data was obtained by conducting research in the laboratory. The sample used a cylindrical concrete with a size of 15 x 30 cm with a total of 30 specimens that will be tested for compressive strength with a Machine Compression testing machine to determine the compressive strength of concrete. The results of this study were the compressive strength of concrete using rainwater pH 5.8 and normal PDAM water pH 7.0 as a comparison. The results showed of compressive strength with water pH 7.0 at the age of 3 days 6,638 MPa, 7 days 11,878 MPa, 14 days 17,567 Mpa, 21 days 19,840 MPa and 28 days 21,490 MPa. While the results of compressive strength with rainwater pH 5.8 at the age of 3 days are 9,107 MPa, 7 days 13,830 MPa, 14 days 16,425, 21 days 16,470 and 28 days 17,982 MPa. From the results of the compressive strength above, it can be concluded that the use of rainwater pH 5.8 in concrete mixtures and curing at the age of 28 days had decreased in compressive strength by 16,32% of the compressive strength of PDAM water. Which indicates that PDAM water pH 7.0 was better for mixing concrete and curing compared to rainwater pH 5.8.
Rainwater Harvesting
Cite
Citations (1)
Compressive mechanical properties were obtained and stress-strain plots were analyzed by means of uniaxial compression tests,which were performed at different strain rate(1/300~1/12 s-1) and temperature(-40~25 ℃) on HTPB propellant.The results show that compression stress and compression modulus increase gradually with decreasing temperature and increasing strain rate,and present linear-log function relation with strain rate(and),which could be used to predict the compression mechanical properties at wide strain rate.In addition,the results of variance analysis indicate that low temperature has significant effect on compression modulus and compression strain,while strain rate has significant effect on compression stress.
Strain (injury)
Stress–strain curve
Cite
Citations (3)
Abstract The aim of this study is to improve the compressive strength of mortar by adding a recycled material (marble powder) at different weights gradually to the mortar. The samples were prepared and treated with different pH solutions to investigate how can effect compressive strength. The results showed that after preparing the sample of mortar by adding different weights of marble powder, the Compressive strength of the sample of (4 gm) weight of marble powder had the highest value comparing with other samples. The compressive strength for the samples were treated with different pH showed that it decreased with increasing acidity (pH from 1 to 6), but the other sample’s compressive strength increased with increasing alkalinity (pH from 8 to 14). At (pH from 1 to 14), the compressive strength was increasing gradually.
Alkalinity
Cite
Citations (3)
Two types of core samples with dimension of 100 mm and 70 mm in diameter are prepared,which were cored from high strength concrete of 50～90 MPa compressive strength.Then,their compressive strength were measured and compared with cubic compressive strength of concrete under same curing conditions.Results indicate that compressive strength of core samples with various dimensions was influenced little by type of aggregate.The compressive strength of core samples with dimension of 100 mm in diameter is almost the same as cubic compressive strength of concrete with dimension of 100 mm in sides.However,the compressive strength of core samples with dimension of 70 mm in diameter is higher by 13% than the cubic compressive strength of concrete with dimension of 100 mm in sides.This shows that it is necessary to modify the compressive strength advisably when small core sample was used to evaluate the compressive strength of high strength concrete.
Core strength
Cite
Citations (0)
Granite Powder (GP) is industrial byproducts generated from the granite polishing and milling industry in powder form. The byproduct is left largely unused and is hazardous materials to human health because they are airborne and can be easily inhaled. GP was used as an additive to the concrete to explore the possibility of increasing the mechanical properties (compressive strength) of the concrete. The slump, compressive strength and water absorption test were performed on fresh and hardened concrete. The addition of GP to concrete to serve as an additive shows an improvement in the compressive strength of the concrete. The highest 3-day compressive strength (23.03 N/mm2) was recorded at 10% GP addition level while the lowest 3-day compressive strength (20.47 N/mm2) was recorded at 2.5% GP addition level. The highest 28-day compressive strength (28.29 N/mm2) was recorded at 10% GP addition level while the lowest 28 days compressive strength (27.40 N/mm2) was recorded at 2.5% GP addition level. Peak compressive strength of 33.40 N/mm2 was obtained at 56 days when 10% GP was added in the concrete production. The workability of the concrete decreased with increase in GP replacements. Therefore a higher water to cement ratio will be required to maintain a certain level of workability. In conclusion, employing GP as an additive in concrete helped in boosting the mechanical properties of concrete. The GP at 10% addition is the best choice among other concrete mixtures as it is equivalent to grade 30 concrete suitable for producing post tensioned concrete.
Cite
Citations (1)
High-strength concrete listed in SNI 03-6468-2000 concrete is defined as concrete having the required compressive strength of fc'≥ 41 Mpa. From this study, data obtained from the compressive strength of concrete at the age of 28 days as follows: the value of the normal concrete compressive strength of 41.72 MPa, the compressive strength of the Sikament-ln mixture of 0.6% slump 5 of 45.65 MPa, the compressive strength of the Sikament-mixed concrete. -ln 1% slump 6 of 47,38 MPa, compressive strength of mixed concrete Sikament-ln 1.4% slump 7 of 44.20 MPa, compressive strength of mixed concrete of Sikament-ln 1.8% slump 8 of 45.65 MPa 38 ,65MPa. It can be seen from the results of this study that the ideal compressive strength is the compressive strength of the Sikament-ln mixture of 1% slump 6 this is because the compressive strength value is much greater than the compressive strength without the Sikament-ln mixture.
Concrete slump test
Cite
Citations (0)
Silica fume
Soft Computing
Cite
Citations (3)
Mode (computer interface)
Magnetic bearing
Failure causes
Cite
Citations (25)
Abstract The influence of calcium chloride (CaCl 2 ) as an accelerator for the compressive strength development of concrete made with type I Portland pozzolan cement (PPC) as a hydraulic binder has been investigated. Natural sand and crushed stone were used as fine aggregate and coarse aggregate, respectively. The mix proportion of concrete, by weight, was 1.0 binder: 2.1 fine aggregate: 3.4 coarse aggregate and the water-binder ratio was 0.57. The calcium chloride added to the concrete mixture was 0%, 1.0%, 1.5%, and 2.0% by binder weight. The compressive strength test was performed at 1, 3, 7, 28, and 90 days. The test results show that adding CaCl 2 to a concrete mixture accelerates the development of compressive strength. The compressive strength gain was about 36–48% at 1 day and about 29–33% at 3 days, compared to control concrete. Moreover, it increases the compressive strength of PPC concrete about 3–16% at 28 days and about 7–19% at 90 days. The optimum dose of CaCl 2 to accelerate the development of compressive strength at the early age and to produce the highest compressive strength in the long-term was about 1.5%.
Pozzolanic reaction
Cite
Citations (9)
Abstract Soft computing methods were used in this research to design and model the compressive strength of high-performance concrete (HPC) with silica fume. Box-Behnken design-based response surface methodology (RSM) was used to develop 29 HPC mixes with a target compressive strength of 80 ± 10 MPa. Cement (450–500 kg/m 3 ), aggregates (1500–1700 kg/m 3 ), silica fume (SF) (20–45% weight of cement) and water-binder (w/b) ratio of (0.24–0.32) were provided as input factors while the compressive strength at 7 and 28 days were analysed as responses. Datasets for the artificial neural network (ANN) prediction were generated from 87 experimental observations from the compressive strength test. Performance indicators such as p-value, coefficient of determination (R 2 ), and mean square error (MSE) were used to assess the models. Results demonstrated that RSM worked relatively well in projecting compressive strength with model p-values < 0.05 and R 2 values of 0.913 and 0.892 for compressive strength at 7 and 28 days, respectively. In addition, RSM performed better in detecting the synergistic effects of the variables on the responses. On the other hand, ANN best generalised the relationship between independent and dependent variables considering the low MSE of 12.32 and 14.60, and high R 2 values of 0.912 and 0.946 for compressive strength at 7 and 28 days, respectively. Model equations were developed to predict the compressive strength of silica-based HPC after 7 and 28 days. It is considered that adopting components from both approaches could help the design process for developing consistent mixes of HPC with supplementary cementitious materials (SCMs).
Silica fume
Cite
Citations (1)