The strength properties of basalt fiber–reinforced biocemented (BFRB) sand specimens with various calcite contents and fiber are investigated through a series unconfined compressive splitting tensile tests. Reverse injection is introduced to improve the uniformity calcium carbonate precipitation. test results show that both (UCS) (STS) at given content increase significantly increasing content, whereas axial strain peak failure state decreases content. improved ductility has implications for...

To effectively stabilize coarse sand, bentonite was introduced in microbially induced carbonate precipitation (MICP) grouting. Varying concentrations (0, 20, 40, and 80 g/L) of were added to bacterial suspensions (BSs), which magnetically stirred form bacterial-bentonite (BBSs). Then, sand specimens treated with BBSs cementation solutions (CSs) different levels. The results showed that the addition could increase volume fractions precipitates consisting calcium (CaCO 3 ) bentonite....

A significant pressing issue in microbially induced calcium carbonate precipitation (MICP) is the characterization of heterogeneous growth mechanics (CaCO3) crystals. This study aimed to visualize bacteria and CaCO3 distributions at quiescent state through microfluidic chip tests where bacterial solution (BS) cementation (CS) were initially injected simultaneously from two separate microchannels subsequently converged a reaction microchannel. The experiments revealed that diffusion within CS...

Microbially induced calcium carbonate precipitation (MICP) has attracted great attention recently for its ability to improve the mechanical properties of soils. Calcium (CaCO3) precipitates that formed at contact points and on surface particles or in pore space soil matrixes could increase bonding strength, friction, interlocking resistances due enhancement interparticle bonds, particle roughness, packing density, therefore, greatly macroscopic performances biocemented soils were subjected...

Enzyme-induced carbonate precipitation (EICP) is an environment-friendly method for improving soil mechanical properties. The extraction and application of plant crude urease reduces the treatment cost. However, in terms efficiency calcium production cementation, considered inferior to pure or bacteria. In this paper, extracted from soybean was used explore effects activity, method, number treatments (NTs), injection rate, curing time on unconfined compressive strength distribution...

ABSTRACT In geo‐energy engineering projects, temperature is an essential environmental variable, and accurately predicting its effect on the thermomechanical properties of geomaterials remains a challenge. Similar to fine‐grained soils, variation also crucial factor that affects stress‐strain response critical state behavior coarse‐grained soils. this study, model established for soils using theories from fractional plasticity. The evolution line with increasing can be well characterized by...

Enzymatically induced carbonate precipitation (EICP) is a potential method to alter the hydraulic properties of fractured rocks. The pore-scale in situ formation bio-mediated precipitated carbonates fracture-mimicking channels was investigated experimentally through visualisation platform and microfluidic technology. Image processing employed analyse behaviour. Three representative biogrouting methods (one-phase continuous injection, one-phase staged injection two-phase injection) role...

We identified a family in which translocation between chromosomes X and 14 was associated with cognitive impairment complex genetic disorder termed "Genetic Epilepsy Febrile Seizures Plus" (GEFS(+)). demonstrate that the breakpoint on chromosome disrupted gene encodes an auxiliary protein of voltage-gated Na(+) channels, fibroblast growth factor 13 (Fgf13). Female mice one Fgf13 allele deleted exhibited hyperthermia-induced seizures epilepsy. Anatomic studies revealed expression mRNA both...

This technical paper investigates the bearing performance of precast concrete piles embedded within calcareous sands with biogrouting at pile toe. Loading tests biogrout-improved and unimproved model were conducted to evaluate biogrout enhance toe capacity piles. The total a biogrouted was 4.4 times as large that without biogrout. A series index performed using penetrometer estimate spatial distribution strength biocemented below It found average sand gradually decreased increasing vertical...

Biomineralization through microbial process has attracted great attention in the field of geotechnical engineering due to its ability bind granular materials, clog pores, and seal fractures. Although minerals formed by biomineralization are generally same as that mineralization, their mechanical behaviors show a significant discrepancy. This study aims figure out differences between mineralization processes visualizing tracking formation using microfluidics. Both occurred Y-shaped...

This paper examines the potential influence of particle-size distribution on stress-dilatancy behavior granular materials from results 35 conventional drained triaxial compression tests. Seven different grain-size curves two (glass beads and Péribonka sand) in range 63–2,000 µm were tested at normal pressures initial relative densities. It was shown that for a given density confining pressure, although shear strength volumetric response independent coefficient uniformity, Cu, investigated...

Soil properties, the chemical composition of cementation solution, injection technique, and environmental conditions have all been extensively studied as variables influencing microbially induced carbonate precipitation performance. However, despite fact that different researchers used bacterial suspensions, influence suspension type, more specifically some organic matters in which can play a key role morphology mechanical properties CaCO 3 , has often overlooked. In this study, harvested...

Upon close scrutiny of data reported in the literature, taking into account particle-scale characteristics to optimize precision well-known empirical Bolton’s equations and imposing particle-size limits on them is recommended. The present paper examines potential influence particle size grading shear strength–dilation relation granular materials from results 276 symmetrical direct tests. applicability physical tests interpret plane strain frictional shearing resistance has been widely...

This study investigated the performance of microbially induced calcite precipitation (MICP) in reinforcing road bases reconstituted with calcareous or silica sands. Four testing models were prepared by surface percolation method at two cementation levels. A series tests for California bearing ratio (CBR) and unconfined compressive strength (UCS) performed to examine biotreated samples model element scales. Scanning electron microscopy (SEM) conducted on specimens sectioned from four base...

Microbial-induced carbonate precipitation (MICP) technique has been adopted in geotechnical engineering widely. In this study, the effect of drying-wetting cycles on MICP-recycled shredded coconut coir (RSC) reinforced calcareous sand was studied, and deterioration mechanism under revealed. Test results indicated that exert an important influence durability MICP-RSC specimens. With increase N, specimens demonstrated significant mass loss rate critical void ratio, decrease maximum shear...

Microorganisms have been essential in the natural world for millions of years, contributing significantly to environmental interaction. It has disoverd that some bacteria are potential geotechnical and engineering due their outstanding ability biomineralization. Therefore, how train as special professional "workers" biomineralization is increasingly a key topic related research fields. This article briefly introduces methods commonly utilized improve adaptability mineralization efficiency...