This study concerned a stretch of 17 km of a 94-km highway alignment in Southeastern Nigeria that has a high incidence of pavement failure arising from subgrade failure. The subgrade of this section of the roadway is composed of Ekenkpon shale, New Netim marl, and Nkporo shale. Under the Unified Soil Classification System, the shales classify as OH (organic clay) and the marl classifies as MH (...

Corrosion of reinforced concrete is one of the major problems in the construction industry causing premature deterioration of concrete structures well before their service life. This has placed incredible financial burden on many projects and also placed safety of users at risk. A research work was carried out to evaluate the effect of water cement ratio on corrosion of steel in reinforced conc...

Xenopus Pitx1 is a homeobox gene whose family members are structurally and functionally conserved in organisms as diverse as Drosophila, chick, mouse, human, and frog. Present as a maternal transcript, the gene is zygotically expressed during gastrulation in a dorsal streak of cells. This streak restricts to a small circular domain underlying the center of presumptive neural plate. Shortly ther...

SVALBARD NORWAY: ANALOGS FOR MARTIAN CARBONATES. D.F. Blake, A.H. Treiman, R. Morris, D. Bish, H.E.F Amundsen, A. Steele and the AMASE team. MS 239-4, NASA Ames Research Center, Moffett Field, CA 94035 USA, [email protected]; Lunar and Planetary Institute, Houston, TX; Johnson Space Center, Houston, TX; Department of Geological Sciences, Indiana University; Earth and Planetary Explorations S...

Macro-defect-free (MDF) cement with high flexure strength has been an active research area over several decades. To study the tensile properties of these materials, it is essential to understand the mode I crack propagation. In this article, cleavage cracking in calcium aluminate cement (CAC)–phenol resin composites is analyzed based on an energy method. The crack-trapping effect of the cement ...

The ternary system of Portland cement-microsilica-limestone has been studied by investigating its set and strength behaviours. A number of different cementitious <span style="font-size: 10pt; color: #0...

A novel injectable bone cement was developed by integration of nano calcium-deficient hydroxyapatite/multi(amino acid) copolymer (n-CDHA/MAC) and calcium sulfate hemihydrate (CSH; CaSO4 · 1/2H2O). The structure, setting time, and compressive strength of the cement were investigated. The results showed that the cement with a liquid to powder ratio of 0.8 mL/g exhibited good injectability and app...

Polyelectrolyte species, known as superplasticizers, dramatically affect the rheological properties of dense cement suspensions. We have studied the influence of sulfonated naphthalene formaldehyde condensate (SNF) and carboxylated acrylic ester (CAE) grafted copolymers of varying molecular architecture on the surface (e.g., adsorption behavior and zeta potential) and rheological properties of ...

In this study, the effects of graphene oxide (GO) on the microstructure of cement mortars were studied using scanning electron microscopy (SEM), thermogravimetric (TG), and X-ray diffraction (XRD) techniques. Cement mortar samples with different proportions of GO (0.02, 0.04, 0.06, and 0.08 wt % based on the weight of cement) were prepared. The test results showed that GO affected the crystalli...