The effects of particle breakage and shape on the strength parameters of sandy soil

Many laboratory and full-scale studies found that pile foundation is a reliable structure that has a long-term durability. This aspect makes it favourable when construction is in an area like the coastal where granular materials are normally in great scale. Generally, method used for the installation of pilling such as the drop hammer method will involve high energy to drive a single pile into the ground. Hence, the soil particles may undergo serious physical changes that will affect the engineering properties of soil used in the design work. The main aim of this research is to know the impact of pile installation work on sand particles. To understand the impact of sand particle breakage to the soil strength, an actual soil breaking mechanism simulated in the laboratory by using an automated soil compactor where the sand samples were crushed using 500 and 1000 times of blows respectively. The behaviour of sand were then analysed using a series of test which are; sieve analysis, specific gravity, relative density and the shear box test in order to measure the engineering properties of the sand. Mackintosh probe test was conducted in-situ to identify the undrained shear strength of sand and to correlate the cohesion of the sand with laboratory testing. This research confirmed that particle breakage has a significant influence with sand shape and therefore its strength changes with crushing impact

Compressive strength and durability of foamed concrete incorporating processed spent bleaching earth

Foamed concrete incorporating processed spent bleaching earth (PSBE) produces environmentally friendly foamed concrete. Compressive strength, porosity, and rapid chloride penetration tests were performed to investigate the potential application for building material due to its low density and porous concrete. Laboratory results show that 30% PSBE as cement replacement in foamed concrete produced higher compressive strength. Meanwhile, the porosity of the specimen produced by 30% PSBE was 45% lower than control foamed concrete. The porosity of foamed concrete incorporating PSBE decreases due to the fineness of PSBE that reduces the volume of void space between cement and fine aggregate. It was effectively blocking the pore and enhances the durability. Consistently, the positive effect of incorporating of PSBE has decreased the rapid chloride ion permeability compared to that control foamed concrete. According to ASTM C1202-19 the foamed concrete containing 30% PSBE was considered low moderate permeability based on its charge coulombs value of less than 4000. Besides, the high chloride ion permeability in foamed concrete is because the current quickly passes through the specimen due to its larger air volume. In conclusion, incorporating PSBE in foamed concrete generates an excellent pozzolanic effect, producing more calcium silicate hydrate and denser foamed concrete, making it greater, fewer voids, and higher resistance to chloride penetration

Long term outcome in unilaterally treated retinopathy of prematurity: a case report.

Retinopathy of prematurity (ROP) is a disorder describing an immature vascularisation of a developing retina in low birth weight preterm infants. This condition potentially leads to blindness. ROP developed as a response of hypoxia of the eye due to incomplete development of the retinal vessels. ROP is commonly reported as bilateral disease,a small percentage of infants have asymmetrical changes. We report a case of long-term outcome of a asymmetry ROP changes with peripheral retinal ablation in a single eye. This particular case demonstrates the possible long-term outcome of unilaterally treated ROP which could either be due to the severity of the disease itself or the treatment she received. It is important to highlight the possibility of unequal development of the eye in asymmetrical presentation of ROP

Absence of toxicity of strobilanthes crispaJuice in acute oral toxicity study in sprague dawley rats

This study evaluated four different doses of Strobilanthes crispa juice (700, 2100, 3500 and 4900 mg kg-1 of body weight) administered orally to normal female and male Sprague dawley rats on possible changes in various physical, behaviour, morphology and biochemical parameter. The rats were treated with a single dose of juice and observed for 14 days. No significant toxicity was observed with respect to clinical parameters and organ morphology. In addition, no significant changes were observed in the level of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, creatinine and albumin. The S. crispus juice was found to be safe at the maximum dose used in this study (4900 mg kg-1 of body weight)

The influence of steel slag as alternative aggregate in permeable concrete pavement

This study identifies the pervious concrete with a high direct runoff on the pavement incorporating steel slag. This study is progressing in two stages i.e. 1ststage is obtaining the best mix design by using cubic concrete samples with dimension of 100mm height based on 7 days compressive strength test. Indeed, different proportion of aggregate and ratio were tested in order to select the highest compressive strength which has reached 10.9 MPa in the first 7 days of curing. The cylindrical concrete sample with the dimension of 200 x 100 mm was used in the 2nd stage. In addition, steel slag was used in the 2nd stage besides the granite aggregate. In fact, three different percentages of steel slag are involved; 50% Steel Slag and 50% Granite; 30% Steel Slag and 70% Granite; and 70% Steel Slag and 30% Granite. Hydrologically, 13.8 mm/s is the highest Infiltration rate that pervious concrete has reached which has been recorded throughout permeability test. The rainfall intensity which plays an important role on the pavement was identified. Thus, intensity distribution frequency curve was developed using MSMA and compared within filtration rate results of pervious concrete. Mix design ten (M10) has the ability to perform efficiently during highest rainfall intensity meanwhile strength needed to be increased since 10.9 MPa in the first 7 days of curing is not sufficient

Estimate the durability of rice husk ash concrete subjected to sulfate attack through wetting and drying cyclic

It is well known that aggressive environments like the sulfate attack are the major factor affecting the durability of concrete. Thus, this research was carried out to estimate the durability of rice husk ash (RHA) concrete exposed to sodium sulfate attack through wetting and drying cyclic. Five levels of cement replacement namely 0, 10, 20, 30 and 40% (by weight) were studied. After being kept in the sodium sulfate solution for 3, 7, 28, 56, 90 and 180 days, the RHA concrete specimens were evaluated based on the rapid chloride permeability and its correlation. It was found that the total charge passed in Portland cement concrete was higher than that of RHA-blended cement concrete. However, it continued to decrease along with increasing levels of RHA replacement. In addition, the use of 40% RHA in the cement resulted in better resistance to sulfate attack when the concrete specimen was exposed to the wetting and drying cycles. It can be concluded that the use of 10 to 40% RHA effectively decreased the penetration depth (charge passed) in the concrete under sulfate attack

Thermal analysis and x-ray diffraction of rice husk ash blended cement under sodium sulfate with wetting and drying cycles

Sulfate attack is one of the most aggressive environmental deterioration affecting the durability of concrete structures. Thus, this study is to evaluate the effect of sodium sulfate (5% Na2SO4) solution on the performance of rice husk ash (RHA) blended cement under drying and wetting cycle, which is thought to simulate an aggressive environment in concrete. The RHA replacement level used was 10%. The performance of the specimen was evaluated by the differential thermal analysis (DTA), thermogravimetric analysis (TGA), and X-ray diffraction (XRD). The results showed that the replacement of ordinary Portland cement by 10% rice husk ash effectively improved the resistance of concrete due to sulfate attack. The result also indicate that the quantity of expansive gypsum formed by the reaction of calcium hydroxide will be less in RHA blended cement than in OPC specimen. In addition, RHA blended cement possibly reduced the potential of ettringite and gypsum formation due to the reduction in the quantity of calcium hydroxide, thus, improved the resistance of concrete to sulfate attack