Effect of microbially induced cementation on the instability and critical state behaviours of Fraser River sand

2020 ◽  
Vol 57 (12) ◽  
pp. 1870-1880 ◽  
Author(s):  
Guillermo Alexander Riveros ◽  
Abouzar Sadrekarimi
Keyword(s):  
Compositional Analysis ◽  
Engineering Properties ◽  
Fraser River ◽  
Calcite Precipitation ◽  
Electron Microscopic ◽  
River Sand ◽  
Cemented Sand ◽  
Direct Simple Shear ◽  
Calcite Cementation ◽  
Metabolic Action

Microbially induced calcite precipitation (MICP) is a naturally driven biological process that harnesses the natural metabolic action of bacteria to induce the precipitation of calcium carbonate and alter soil engineering properties. This paper presents the results of using MICP to improve the monotonic undrained yield and critical strengths of Fraser River sand specimens. Bacteria called “Sporosarcina ureae” are employed as a ureolytic organism to achieve MICP. The formation of calcite cementation among sand particles is confirmed using scanning electron microscopic images and X-ray compositional analysis of cemented sand clusters. The progress of MICP cementation is assessed by measuring the velocity of a shear wave (VS) traveling through the specimen. The results show that VS starts to increase just as the calcium solution is introduced into each specimen after soaking the samples with the bacterial solution. Improvement in monotonic strength of sand samples is subsequently measured in a series of direct simple shear tests. Due to the combined effects of particle cementation and densification, the sand’s undrained and drained monotonic shearing strengths are significantly enhanced.

Hybrid bacteria mediated cemented sand: Microcharacterization, permeability, strength, shear wave velocity, stress-strain, and durability

2021 ◽  
pp. 105678952199119
Author(s):  
Meghna Sharma ◽  
Neelima Satyam ◽  
Krishna R Reddy
Keyword(s):  
Synergistic Effects ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Engineering Properties ◽  
Calcite Precipitation ◽  
Stress Strain ◽  
Split Tensile Strength ◽  
Cemented Sand ◽  
The Individual

Microbially induced calcite precipitation (MICP), a sustainable approach for sand biocementation, was investigated in previous studies based on metabolic activity of individual microorganisms. The individual bacteria, specifically Sporosarcina pasteurii (SP), Bacillus subtilis (BS), and Lysinibacillus sphaericus (LS), were found capable enough for sand biocementation. However, present study investigates synergistic effects of using bacterial-hybrids on cementation and consequent improvement in sand properties. The SP, BS, and LS strains were used in different combinations to create bacterial-hybrids and applied under simulated non-sterile field conditions. Initially, sand biotreatment was carried out in plastic tubes up to 14 days, using bacterial mixtures and 0.5 M cementation solution. Biocemented specimens were tested for calcite precipitation, XRD, FTIR, and SEM. The SP and LS combination (SPLS hybrid) showed maximum calcite precipitation, which is further used for biotreatment to create cylindrical sand samples for testing improved engineering properties. These samples were prepared using 0.5 M cementation solution in three pore volumes (1, 0.75, and 0.5 PV) and treatment cycles (12, 24, and 48 hrs TC) up to 18 days. Biocemented samples were tested for permeability (6th, 12th, and 18th days of biotreatment), unconfined compressive strength (UCS), split tensile strength (STS), ultrasonic pulse velocity (UPV), and consolidated undrained stress-strain response. Durability of biocementation was also investigated by determining reduction in strength and UPV subjected to freeze-thaw (FT) cycles (5, 10, 15, and 20). The results showed maximum UCS of 1902 kPa, STS of 356 kPa, UPV of 2408 m/s, and coefficient of permeability reduction up to 91%. The higher results were achieved with 11.11% calcite content in 1PV-12TC treated samples. The 1PV-12TC treated samples resulted in 4.2%, 8.3%, 17%, and 35% reduction of strength after 5, 10, 15, and 20 FT cycles, respectively. Overall, biocementation using hybrid bacteria is shown significant to improve sand's engineering properties, including potential to mitigate liquefaction.

Cyclic loading response of loose air-pluviated Fraser River sand for validation of numerical models simulating centrifuge tests

2005 ◽  
Vol 42 (2) ◽  
pp. 550-561 ◽  
Author(s):  
Dharma Wijewickreme ◽  
Somasundaram Sriskandakumar ◽  
Peter Byrne
Keyword(s):  
Cyclic Loading ◽  
Simple Shear ◽  
Mechanical Response ◽  
Shear Loading ◽  
Shear Stresses ◽  
Fraser River ◽  
River Sand ◽  
Cyclic Shear ◽  
Direct Simple Shear ◽  
Static Shear

Cyclic loading response of loose Fraser River sand was investigated, as input to numerical simulation of centrifuge physical models, using constant-volume direct simple shear tests conducted with and without initial static shear stress condition. Although the observed trends in mechanical response were similar, air-pluviated specimens were more susceptible to liquefaction under cyclic loading than their water-pluviated counterparts. Densification due to increasing confining stress (stress densification) significantly increased the cyclic resistance of loose air-pluviated sand, with strong implications for the interpretation of observations from centrifuge testing. The stress densification effect, however, was not prominent in the case of water-pluviated specimens. The differences arising from the two specimen reconstitution methods can be attributed to the differences in particle structure and highlight the importance of fabric effects in the assessment of the mechanical response of sands. The initial static shear stresses appear to reduce the cyclic shear resistance of loose air-pluviated sand in simple shear loading, in contrast to the increases in resistance reported on the basis of data from triaxial testing. Data from laboratory element tests that closely mimic the soil fabric and loading modes of the centrifuge specimens are essential for meaningful validation of numerical models.Key words: liquefaction of sands, air-pluviation, cyclic loading, direct simple shear testing, specimen preparation, fabric.

scholarly journals Effects of Different Types of Fibers on the Physical and Mechanical Properties of MICP-Treated Calcareous Sand

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 268
Author(s):  
Jitong Zhao ◽  
Huawei Tong ◽  
Yi Shan ◽  
Jie Yuan ◽  
Qiuwang Peng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Glass Fiber ◽  
Physical And Mechanical Properties ◽  
Polyester Fiber ◽  
Engineering Properties ◽  
Fiber Types ◽  
Calcite Precipitation ◽  
Calcareous Sand ◽  
Hemp Fiber

Microbial-induced calcite precipitation (MICP) has been a promising method to improve geotechnical engineering properties through the precipitation of calcium carbonate (CaCO3) on the contact and surface of soil particles in recent years. In the present experiment, water absorption and unconfined compressive strength (UCS) tests were carried out to investigate the effects of three different fiber types (glass fiber, polyester fiber, and hemp fiber) on the physical and mechanical properties of MICP-treated calcareous sand. The fibers used were at 0%, 0.10%, 0.15%, 0.20%, 0.25%, 0.30%, 0.35%, and 0.40% relative to the weight of the sand. The results showed that the failure strain and ductility of the samples could be improved by adding fibers. Compared to biocemented sand (BS), the water absorption of these three fiber-reinforced biocemented sands were, respectively, decreased by 11.60%, 21.18%, and 7.29%. UCS was, respectively, increased by 24.20%, 60.76%, and 6.40%. Polyester fiber produced the best effect, followed by glass fiber and hemp fiber. The optimum contents of glass fiber and polyester fiber were 0.20% and 0.25%, respectively. The optimum content of hemp fiber was within the range of 0.20–0.25%. Light-emitting diode (LED) microscope and scanning electron microscope (SEM) images lead to the conclusion that only a little calcite precipitation had occurred around the hemp fiber, leading to a poor bonding effect compared to the glass and polyester fibers. It was therefore suggested that polyester fiber should be used to improve the properties of biocemented sand.

Mechanical Behavior of Microbially Induced Calcite Precipitation Cemented Sand

2021 ◽  
Author(s):  
Igor Marasini de Rezende ◽  
Pedro Domingos Marques Prietto ◽  
Antônio Thomé ◽  
Francisco Dalla Rosa
Keyword(s):  
Mechanical Behavior ◽  
Calcite Precipitation ◽  
Cemented Sand ◽  
Microbially Induced Calcite Precipitation

scholarly journals Suitability of Scoria as Fine Aggregate and Its Effect on the Properties of Concrete

2019 ◽  
Vol 11 (17) ◽  
pp. 4647 ◽  
Author(s):  
Warati ◽  
Darwish ◽  
Feyessa ◽  
Ghebrab
Keyword(s):  
Construction Materials ◽  
Energy Utilization ◽  
Engineering Properties ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Test Results ◽  
River Sand ◽  
Conventional Concrete ◽  
Efficient Energy ◽  
Concrete Production

The increase in the demand for concrete production for the development of infrastructures in developing countries like Ethiopia leads to the depletion of virgin aggregates and high cement demand, which imposes negative environmental impacts. In sustainable development, there is a need for construction materials to focus on the economy, efficient energy utilization, and environmental protections. One of the strategies in green concrete production is the use of locally available construction materials. Scoria is widely available around the central towns of Ethiopia, especially around the rift valley regions where huge construction activities are taking place. The aim of this paper is therefore to analyze the suitability of scoria as a fine aggregate for concrete production and its effect on the properties of concrete. A differing ratio of scoria was considered as a partial replacement of fine aggregate with river sand after analyzing its engineering properties, and its effect on the mechanical properties of concrete were examined. The test results on the engineering properties of scoria revealed that the material is suitable to be used as a fine aggregate in concrete production. The replacement of scoria with river sand also enhanced the mechanical strength of the concrete. Generally, the findings of the experimental study showed that scoria could replace river sand by up to 50% for conventional concrete production.

Evaluation of the in situ state of Fraser River sand

1997 ◽  
Vol 34 (4) ◽  
pp. 510-519 ◽  
Author(s):  
A V Chillarige ◽  
P K Robertson ◽  
N R Morgenstern ◽  
H A Christian
Keyword(s):  
Fraser River ◽  
River Sand

Surface Morphology and Compositional Analysis of Undoped Amorphous Carbon Thin Films via Bias Assisted Pyrolysis-CVD

2013 ◽  
Vol 667 ◽  
pp. 468-476 ◽  
Author(s):  
A. Ishak ◽  
K. Dayana ◽  
Mohamad Rusop
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Amorphous Carbon ◽  
Palm Oil ◽  
Compositional Analysis ◽  
Silicon Surfaces ◽  
Silicon Substrates ◽  
Negative Bias ◽  
Electron Microscopic ◽  
P Type

Amorphous carbon (a:C) were successfully deposited on the silicon surfaces via bias assisted pyrolysis-CVD in the range between 350oC to 500oC with constant of negative bias -50V in 1 hour deposition. The heated of palm oil at about 150oC was vaporized then used for deposited onto p-type silicon substrates. The deposited thin films were characterized by using field emission scanning electron microscopic (FESEM), energy dispersive analyser x-ray (EDAX). We have found carbon element at about 0.15 keV from EDAX with surface morphology formed a nano-ball like structure at 450oC of palm oil precursor. These results indicated deformation of physical and structural thin films caused by applied negative bias and the temperature.

scholarly journals Strength and Microstructure of Concrete with Iron Ore Tailings as Replacement for River Sand

2018 ◽  
Vol 34 ◽  
pp. 01003 ◽  
Author(s):  
Ali Umara Shettima ◽  
Yusof Ahmad ◽  
Mohd Warid Hussin ◽  
Nasiru Zakari Muhammad ◽  
Ogunbode Eziekel Babatude
Keyword(s):  
Iron Ore ◽  
Economic Value ◽  
Waste Product ◽  
Construction Materials ◽  
Sustainable Construction ◽  
Electron Microscopic ◽  
River Sand ◽  
Iron Ore Tailings ◽  
Concrete Production ◽  
And Performance

River Sand is one of the basic ingredients used in the production of concrete. Consequently, continuous consumption of sand in construction industry contributes significantly to depletion of natural resources. To achieve more sustainable construction materials, this paper reports the use of iron ore tailings (IOT) as replacement for river sand in concrete production. IOT is a waste product generated from the production of iron ore and disposed to land fill without any economic value. Concrete mixtures containing different amount of IOT were designed for grade C30 with water to cement ratio of 0.60. The percentage ratios of the river sand replacements by IOT were 25%, 50%, 75% and 100%. Concrete microstructure test namely, XRD and Field Emission Scanned Electron Microscopic/Energy dispersive X-ray Spectroscopy (FESEM/EDX) were conducted for control and IOT concretes in order to determine the interaction and performance of the concrete containing IOT. Test results indicated that the slump values of 130 mm and 80 to 110 mm were recorded for the control and IOT concretes respectively. The concrete sample of 50% IOT recorded the highest compressive strength of 37.7 MPa at 28 days, and the highest flexural strength of 5.5 MPa compared to 4.7 MPa for reference concrete. The texture of the IOT is rough and angular which was able to improve the strength of the concrete.

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