Nowadays, one of the most desirable alternatives to cement-based composites is the alkali-activated blends which can be towards achieving more durable materials. In alkali-activated slag/pumice (AASP) mortars, ground granulated blast-furnace slag (GGBFS) could be replaced partially with Volcanic pumice powder (VPP) as a natural pozzolan; however, its performance in alkali-activated slag/pumice (AASP) mortars against mineral acid environments are currently missing in the literature. In this paper, the durability of AASP mortars containing 0 or 10% VPP activated by the combination of sodium silicate with NaOH or KOH exposed to a high concentration of sulphuric and nitric acids were investigated. In addition to flowability, capillary water absorption, and mercury intrusion porosimetry tests, deterioration due to the mineral acid attack was examined using visual condition assessment, mass loss, compressive strength change, and X-ray diffraction analysis (XRD). A comparison was also performed with ordinary Portland cement (OPC) mortar specimens as a reference mixture. It was found that the AASP mortars are more durable than a corresponding OPC mortar in terms of mass and compressive strength changes in sulphuric and nitric acid solutions. Generally, employing 10% VPP exhibited no significant effect on the durability of AASP mortars against mineral acid attack. In addition, utilizing NaOH alkali activator could be a better choice in exposure to sulphuric acid, but in nitric acid solution, KOH-activated samples revealed better durability in terms of mass and compressive strength change.

Fiber reinforced concrete (FRC) has been widely used due to its advantages over plain concrete such as high energy absorption, post cracking behaviour, flexural and impact strength and arresting shrinkage cracks. But there is a weak zone between fibers and paste in fiber reinforced concretes and this weak zone is full of porosity, especially in hybrid fiber reinforced concretes. So it is necessary to apply a material that reduces porosity and consolidates this transition zone. In this research first, the flexural and impact resistance tests were carried out on hybrid fiber reinforced concretes to choose the optimum percentage of steel and polypropylene fibers based on flexural toughness, modulus of rupture and impact resistance. Finally, compressive strength tests were conducted on selected hybrid fiber reinforced concretes containing pumice and metakaolin to choose the better pozzolan and replacement level based on compressive strength test. Results showed that, metakaolin with 15% substitution for cement had a significant role in increasing compressive strength. However, pumice did not act on the same basis.

Lightweight aggregate concretes are widely incorporated in construction and development.This study, presents an experimental investigation on the properties of volcanic pumice lightweight aggregates concretes. To this end, two groups of lightweight concretes (lightweight coarse with natural fine aggregates concrete, and lightweight coarse and fine aggregates concrete) are built and the physical/mechanical and durability aspects of them are studied. The results of compressive strength, tensile strength and drying shrinkage show that these lightweight concretes meet the requirements of the structural lightweight concrete.Also, the cement content is recognized as a paramount parameter in the performance of lightweight aggregate concretes.

Introduction: Phosphate is known to be the main limiting elements in the reuse of wastewater effluents and then it is the key element to outbreak of eutrophication. Therefore the objective of this work was to investigate the adsorption of phosphorous by natural and surface modified pumice with H2O2.Methods: The present work was a fundamental-practical study which done in batch system. In this work, natural and modified pumice were used for removal of phosphorous from aqueous solution. Several experimental parameters including pH (2-10), adsorbent mass (2-10 g/L), initial phosphorous concentration (5-20 mg/L), ionic strength and contact time were studied. All experiments were conducted in batch system with varying one experimental parameter, while others were constant.Results: The results show that modification of pumice with H2O2 will improve adsorbent sorption capacity without any structural distortion. In addition, higher removal efficiency was observed at 10 g/L of adsorbent dose, pH 6, 130 min contact time and 20 mg/L of phosphorus concentration. In the optimal conditions, 69% and 97% of phosphorus removal were achieved by natural and modified pumice adsorbents, respectively. In addition, removal efficiency decreased for increasing ionic strength. Pseudo second order kinetic model best describe adsorption of phosphorus onto used adsorbent.Conclusion: The results of present work well demonstrate that pumice have substantial adsorption capacity for phosphorus and in the case of its modification, its adsorption capacity will be improved.

Iron is the 4th abundant elements of the earth’s crust which high sub standard quantity of it in water distribution systems causes improper effects .The main objective of this research is to use Pumice stone for eliminating or decreasing of soluble Iron in water and to study in detail the effect of its factors. Three levels of Iron concentrations were prepared (0.3, 1 and 5 mg/L) and poured in a batch system in two Levels 10 and 20 g of Pumice stone. The pH were set at three levels (3.5, 7 and 10) .The remaining Iron concentration was measured in each step of process by taking a sample in every 10 minutes using spectrometry method. The results showed that adsorption rate had a direct relation with adsorbent and soluble pH. Also in this method the used Pumice stone can be reused and regenerated. Iron absorption data can be presented by freundlich isotherm model. According to the results obtained, Pumice stone can be used with high efficiency in adsorption process of Iron from water and wastewater. Also low cost and easy accessibility of Pumice stone along with its possibility for reused and regeneration are other advantages of this stone for full-scale application.

In this study, for the first time, Pumices around Damavand Mountain is studied by IRS-1C, Aster and ETM+ images. For this purpose at first, all images are preprocessed. It means geometric corrections and registering images together and with topography maps (1:25000) are done. Then atmospheric corrections, calibration of radiance and reflectance and topographic correction with Minneart method are done too. Preprocessing, some techniques like PCA, IHS, OIF, FCC and SAM have been done. Pan image of IRS-1C satellite for data fusion in visible and near infrared of Aster at visual interpretation and recognizing of roads and mines is better than ETM images. After data preprocessing, some techniques like PCA, IHS, OIF, FCC and SAM have been done. Pan image of IRS-1C satellite for data fusion in visible and near infrared of Aster at visual interpretation and recognizing of roads and mines is better than ETM images. IHS and PCA methods equally have separated clearly Pumice mines and trachyandesites without vegetations and soils covers. With respect to VNIR of Aster has more intensity than other spectral areas. Also because of high topographic changes and pampas vegetation, visible bands and Very Near Infrared (VNIR) of Aster aren't too useful. These spectral areas are caused mixing classes together, especially limestones and pumice. Totally for most of stones and different ores, spectral area of Short Wave Infrared (SWIR) of Aster has the best ability. For categorizing and extracting pumices potential layers from images, sampling is done on pixel or pixels that contain pumice mines. Because of less expansion of mines, samples are picked up on just one pixel or in maximum case ten pixels. According to that limitation, Spectral Angle Method (SAM) technique has more ability than the other methods. Use of DEM for separation flat or low dip lands whereas are placed for Pumices in northern, eastern and some southern parts of studied area is effective, but any worthwhile tracks of pumice weren’t found in south-west of mountain. Finally mining hopeful areas in cast of mining potential map is prepared. By calculating the overlay of effective geology structure layer with pumice mines areas layer, which is extracted from PAN image, the amount of overlay is calculated ninety three percent.

Previous researches have shown that due to its good adhesion, alkali-activated materials can be used as a protective overlay for concrete structures. However, the mechanical properties and durability of alkali-activated materials are not fully investigated. In this paper, compressive strength, bond strength, water penetration and half-cell corrosion potential of alkali-activated slag and pumice mortars as concrete overlay are investigated. The results show that the performance of alkali-activated slag mortar is better than Portland cement one in above tests and the use of potassium hydroxide as activator and a mixture of 90% slag and 10% pumice as based material result in the highest compressive strength and bond strength and the lowest water permeability and half-cell corrosion potential. The initial half-cell potential reading of alkali-activated mortar specimens was an average of 1. 9 times more than Portland cement mortar specimens. This difference indicates that the ranges presented in ASTM C876 and their relationship with rebar corrosion risks are not applicable for alkaliactivated materials and it is necessary to provide other criteria for these materials. Also, due to different conductivity of alkali-activated and Portland cement mortars, applying potential difference to accelerate the penetration of chloride ions and comparing the performance of alkali-activated materials with Portland cement is not a correct method. However, this method is suitable for comparing mixes design of alkali-activated mortars and its results are in accordance with non-accelerated methods.

Open graded asphalt is used as a wearing course to provide both increased safety in wet weather (through reduced surface water and spray during rain) and reduced noise levels. In this study, Pumice aggregates were applied as a portion of fine aggregate for the improvement of dynamical specification of porous asphalt and the Cantabro, Los Angeles abrasion, and the bitumen precipitation tests were conducted. First, the amount of optimized bitumen related to each of the three types of aggregates and fine Pumice has been estimated, then the properties of the Marshall Resistance and indirect tensile strength have been assigned. Mixtures with 5 percent of fine Pumice has shown better characteristics in Marshall test as well as indirect tensile strength. Also, the results of dynamic creep test showed that the rutting potential decreased by using Pumice aggregate. There is the best amount of permanent deformation for mixtures containing 5% Pumice.

Solute transport parameters, similar to soil's physical and chemical properties, can be affected by the presence of organic and mineral soil conditioners. In this study, the effect of different levels (0, 3, and 6 weight percent) of the inexpensive and easily accessible pumice conditioner on the parameters of bromide transport in sandy loam soil columns (diameter and height of 10 cm) was investigated. The transport parameters were estimated based on the BreakThrough Curves (BTCs) by the inverse modeling of the Convection-Dispersion Equation (CDE) and the mobile-immobile model (MIM) using the CXTFIT software. The BTCs showed that bromide transport in the sandy loam soil columns, regardless of the presence of pumice was mainly equilibrium, and the CDE was more efficient than the MIM, which is based on non-Fickian and non-equilibrium transport. The peak of the BTCs (maximum relative concentration) was lower in the treatments containing pumice and belonged to more pore volume than the controlled treatment did. This indicates a lack of preferential flow and thus, a reduction in the amount of bromide consumed in the treatments containing pumice. The increase in pumice content did not have a significant effect on the parameters of mobile water fraction (𝛽, ) and mass transfer coefficient (𝜔, ) in the MIM, confirming the equilibrium transport of bromide. A 3% increase in the pumice content in the soil caused an increase and a decrease of 47% in dispersivity (𝜆, ) and Peclet number (Pe), respectively. In general, it can be concluded that the use of pumice in field conditions can prevent water loss and nutrients and reduce groundwater contamination by reducing preferential paths.

Self-compacting lightweight concrete (SCLC) is a novel type of concrete that combines the benefits of the lightweight and self-compacting concrete (SCC) types. In this research, the optimal amount of metakaolin used in lightweight concrete containing pumice has been obtained based on the best concrete performance in terms of the greatest simultaneous increase in compressive, tensile and flexural strengths. After choosing the SCLC mixing scheme, L-Box, V-Funnel, Slump flow, and T50 tests were performed to investigate the flowability, passing ability, viscosity, and concrete resistance against segregation. Then, the mechanical properties of SCLC have tested by replacing metakaolin with 0, 5, 10, 15, and 20% by weight of cement. The research results have demonstrated that metakaolin enhances ‎the mechanical strength of SCLC. In addition, by adding metakaolin in the amount of 15% cement weight, the process of improving concrete strength continues. The 28-day SCLC specimens containing 15% metakaolin had compressive, splitting tensile and flexural strength of 26%, 14%, and 11% higher than those of SCLC without metakaolin, respectively. Furthermore, formulas that can ‎predict compressive strength, tensile strength, and ‎flexural strength of 28-day SCLC ‎containing ‎metakaolin have been presented.