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Particle breakage is one of the issues that significantly affect the strength characteristics of aggregate. In this paper, the strength of pre-crushed limestone aggregate was evaluated through investigating the friction angle, stress-strain behaviour, and single-particle strength. The particle breakage phenomenon was studied for samples prepared at different conditions, including non-soaked samples, water-soaked samples, and acid-soaked samples. The purpose of preparing the samples at different conditions was to simulate the effect of environmental factors on the breakage behaviour of limestone aggregate. The test program of this paper consists of two phases of triaxial tests: the initial shearing and second shearing. The test results showed remarkable variations among the samples since limestone aggregate tended to experience more particle breakage after being soaked in water and acid solution. Also, the volume change results exhibited an increase in dilation as the breakage index increases. The test results of this study presented the importance of considering the role of environmental factors in evaluating the particle breakage of limestone aggregate.

This paper examines the effectiveness of using varying proportion (2%, 4% and 6% by dry weight of soil) of a newly formulated biomass silica soil stabiliser (BSS) on tropical lateritic clay which has deleterious effects on construction materials due to its high amounts of SiO2 and Fe2O3. A series of laboratory experiment testing methods: i.e. particle size distribution, Atterberg Limits, linear shrinkage, pH value, compaction, California Bearing Ratio, unconfined compression test, and cyclic load triaxial test were conducted in accordance to BS1377:1990 and AASHTO T307–99:2003 to examine the geotechnical properties of the BSS structured lateritic clay subjected to 0, 7, 14 and 28 curing days. Physicochemical tests such as X-ray fluorescence (XRF), X-ray diffraction (XRD) and field-emission scanning electron microscope (FESEM) were conducted to further support the mineralogical composition and microstructure evidence of the structured soil and substantiate the interpretation of the mechanical strength data. The test results reveal that the notable changes in the properties and behavior of structured lateritic clay was governed by the BSS proportion and curing period. There is an immediate enhancement in the geotechnical properties of the 2% BSS structured lateritic clay, altering soil type from CH to MH before curing begin. The unconfined compressive test results indicate a distinct effectiveness in stabilizing lateritic clay, from 400 kPa to 3675 kPa for 6% BSS structured lateritic clay cured to 28 days. Both soaked and unsoaked California Bearing Ratio (CBR) values were 12.4 and 5.8 folds higher than that of the virgin lateritic clay. The cyclic load triaxial test reveals that the resilient modulus, MR of the structured soil was significantly increased. For full-scale applications, the association between the mechanical properties and linear shrinkage test results deduce that the optimum proportion of BSS required for an effective stabilisation performance is 6%. Finally, the mechanisms of the microstructural changes in the stabilisation process were mainly attributed to the agglomeration and aggregation of the cemented particle through composition of calcium silicate hydrate cementitious products evidenced in the physicochemical tests.

Loess is a typical collapsible soil, which is widely distributed in the upper and middle areas around the Yellow River of China. The stabilization of loess with lime provides a significant improvement in the physical and the mechanical characteristics of the loess and is therefore widely used in the pavement base and subgrade. Therefore, a systematic investigation of Mohr-Coulomb failure envelope of lime stabilized loess needs to be conducted. In this pursuit, the present research envisages the investigation of the effects of the lime content, porosity and curing time on the strength parameters (friction angle (&phi, ) and cohesion (c)), using a series of triaxial tests performed on lime stabilized loess specimens. The experimental results revealed that the friction angle (&phi, ) was independent of the lime content, the porosity and the curing time of the specimen for a given lime stabilized loess, while the factors mentioned above had a significant effect on the cohesion (c) of the lime stabilized loess. For a relatively short curing time (7 days), the change in the lime content did not present an obvious effect on the cohesion (c) of the stabilized loess. However, when the curing time (28, 90 and 180 days) was longer, the increase of the lime content significantly enhanced the cohesion of the stabilized loess. When the lime content was constant, the cohesion (c) of the stabilized loess increased linearly with the decrease in the void ratio. A power function equation was proposed to assess the comprehensive influences of the factors like the lime content, porosity and curing time on cohesion (c). Finally, the Mohr-Coulomb failure envelopes were drawn based on the triaxial test for 47 specimens with various curing time and confining pressure, and the shear strength parameters obtained by the proposed equation were also compared with the experimental results.

This study aimed to investigate the feasibility of using polypropylene fiber-cement-stabilized coastal clay as base-course material or foundation material for city sustainable development by assessing its mechanical performance. The influence of the number of freeze–thaw cycles and curing ages on the mechanical properties of ordinary cemented clay (OCC) and polypropylene fiber-cemented clay (PCC) was investigated by using unconfined compressive test. The experimental results show that the addition of fiber with 1% content can increase the strength as well as the ductility of cemented clay by 12.5% and 15.6%, respectively. The strength of PCC and OCC at 22d age was 1.5 times than at 7d age. Under differently timed freeze–thaw cycles, the mechanical performance of PCC is improved, and, better than that, OCC improves by 11.8% in strength, 16.5% in strain and by 5% in degree of damage, indicating that fiber can improve the freeze–thaw resistance of cemented clay. The frost resistance of PCC and OCC increases with the increase in curing age. Finally, the variation of strength of OCC was explained through the change of micro-structure while the strength enhancing mechanism of polypropylene fiber for cemented clay was also revealed.

This study aimed to investigate the feasibility of using lime&ndash, slag stabilized loess as base-course material by assessing its unconfined compressive strength (UCS). Loess stabilized with various mix ratios were compacted and cured to three, five, seven, and 28 days, respectively, for further strength tests. The effects of binder content, lime-to-slag (L/S) ratio, porosity, and curing time on the UCS of stabilized loess were addressed in detail. The test results show that UCS increases with the increase in binder content or curing time, and it gains strength rapidly within the first seven days of curing. At the same binder content, UCS decreases with the decrease in L/S ratio or porosity. Finally, the correlations of UCS with binder content, porosity, and curing time were derived, which exhibited reasonable correlation coefficients R2 (from 0.86 to 0.97).

We illustrate a case involving a 51-year-old man who presented to a tertiary hospital with sepsis secondary to an abscess of the nasal vestibule and pustular eruptions of the nasal mucosa. Associated cellulitis extended across the face to the eye, and mucosal thickening of the sinuses was seen on computed tomography. The patient underwent incision and drainage and endoscopic sinus surgery. Blood cultures and swabs were positive for a gram-negative bacillus,Burkholderia pseudomallei. He had multiple risk factors including travel to an endemic area. The patient received extended antibiotic therapy in keeping with published national guidelines. Melioidosis is caused byBurkholderia pseudomallei, found in the soil in Northern Australia and Asia. It is transmitted via cutaneous or inhaled routes, leading to pneumonia, skin or soft tissue abscesses, and genitourinary infections. Risk factors include diabetes, chronic lung disease, and alcohol abuse. It can exist as a latent, active, or reactivated infection. A high mortality rate has been identified in patients with sepsis. Melioidosis is endemic in tropical Northern Australia and northeastern Thailand where it is the most common cause of severe community-acquired sepsis. There is one other report of melioidosis in the literature involving orbital cellulitis and sinusitis.