Effect of the Type of Lateritic Soil on the Effectiveness of Geomechanical Improvement Using a Low Quantity of Cement for Sustainable Road Construction.

In Burkina Faso, the most commonly used road construction material is lateritic soil. However, in its raw state, this soil does not meet the required recommendations. To overcome this problem, previous studies have often focused on improving these soils by adding cement. However, these studies have rarely included a multi-criteria characterisation of the main geomechanical parameters of treated soils. It was also noted that the identification parameters of lateritic soils could have an influence on their improvement with cement. The aim of this study is to highlight the influence of the physical and mineralogical properties of lateritic soils on the effectiveness of improving their geomechanical properties by adding a low content of cement (<3% wt.). The soils were taken from two sites: Saaba (LAS) and Kamboinsé (LAK). The effects of cement addition on the plasticity index, CBR index, Young's modulus, unconfined compressive strength, tensile strength and shear strength were studied. In their raw state, LAS and LAK have different physical properties and cannot be used as sub-bases. The addition of cement improves the overall physical and mechanical properties of both soils, but to different degrees. Indeed, after adding 3% cement to the raw soils, the CBR index of LAS increases by 1275% compared with 257% for LAK; the unconfined compressive strength of LAS is twice as high as that of LAK, and the Young's modulus increases by around 460% for LAS compared with 360% for LAK. After improvement, these two soils met all the CEBTP specifications except for tensile strength. The effect of cement was more significant on LAS due to its better physical properties and higher clay mineral content, which would improve pozzolanic reactivity during cement hydration. Knowing the mineralogy of lateritic soils when treating them with cement would allow us to reduce the quantity of cement, thereby mitigating its negative impact on the environment.

[Difficulties in the management of cerebral venous thrombosis (CVT) complicated by subarachnoid hemorrhage (SAH) in infants: about a case]. / Difficultés de la prise en charge d'une thrombose veineuse cérébrale (TVC) compliquée d'hémorragie sous arachnoïdienne (HSA) chez le nourrisson: à propos d'un cas.

CVT is generally rare, particularly among infants. The occurrence of a SAH associated with CVT is very uncommon and only a few cases have been reported in the literature. Symptoms are variable and often misleading. Outcome can be lethal or it can cause potentially severe sequelae if it is not treated or treated late. We report the case of a 22-month old infant examined for convulsions with Stage II coma, intracranial hypertension syndrome and infectious syndrome. Laboratory tests showed pseudomonas spp sepsis and cerebral CT scan allowed the diagnosis. Treatment was based on antibiotic therapy but mainly on anticoagulation therapy. The patient had a significant clinical improvement and follow-up cerebral CT scan showed disappearance of thrombosis with sequellar right hemoragic images. CVT is a severe disease, usually of infectious origin. Anticoagulant therapy is controversial, in particular in patients with associated hemorrhage, but clinical experience supports the effectiveness and safety of this treatment.

[Portal cavernoma in children revealed by gastrointestinal haemorrhage: about a case]. / Cavernome portal chez l'enfant révélé par une hémorragie digestive: à propos d'un cas.

Portal cavernoma is a venous vascular anomaly characterized by the formation of a network of veins whose caliber is increased and carrying portal blood. It is due to a thrombotic and always chronic occlusion of the extra-hepatic portal venous system. This is one of the most common causes of portal hypertension in children. Its severity is mainly associated with an high risk of gastrointestinal haemorrhage. Very few cases have been described mainly in African literature. We report the case of a 4-year old boy admitted with very abundant haematemesis, melena and dizziness associated with anemic syndrome on examination. Laboratory tests showed severe microcytic hypochromic anemia with normal renal and hepatic function. Gastrointestinal endoscopy showed esophageal varices (grade III) with red signs. Abdominal ultrasound showed portal vein formation resulting in the classic "spiderweb", in favor of a cavernoma. Abdominal CT scan confirmed portal cavernoma associated with portal hypertensive syndrome and vascular anomaly like an ectopic splenic vein anastomosis with the trunk formed by the gonadal vein and the inferior mesenteric vein. Therapeutic approach was based on blood transfusion and beta-blocker treatment. Portal cavernoma can be a major complication of vascular malformations often unknown. In case of gastrointestinal haemorrhage in children, diagnosis should be suspected. Its management requires early treatment and should be adapted to the patient's condition in order to prevent a fatal evolution.