Pulp mill fly ash for stabilization of low-volume unpaved forest roads — field performance

2014 ◽  
Vol 41 (11) ◽  
pp. 955-963 ◽  
Author(s):  
Maria Arm ◽  
Jenny Vestin ◽  
Bo B. Lind ◽  
Anders Lagerkvist ◽  
Desirée Nordmark ◽  
...  

Increased temperatures and rainfalls will give more settlements and less bearing capacity in gravel roads, which will have implications for the forestry. Pulp mill fly ash without additives was used for stabilizing the road base of a low-volume gravel road. A two-year monitoring of the road was conducted, including measurements of achieved ash content, density, water infiltration capacity, and load bearing capacity. The results showed that the ash-stabilized sections performed better than conventionally upgraded sections and also achieved increased bearing capacity over time. Hydration of the fly ash increased the stiffness and decreased the permeability of the road base. The differences were more pronounced during spring thaw. Best performance was achieved in the section with thicker ash stabilized layer.

2012 ◽  
Vol 174-177 ◽  
pp. 676-680
Author(s):  
Fang Xu ◽  
Ming Kai Zhou ◽  
Jian Ping Chen

The unconfined compressive strength is used to be the valuation index, the mechanical performance of three kinds of new road base material, which are fly ash stabilized steel slag sand (FA-SS for short), lime and fly ash stabilized steel slag sand (L-FA-SS for short), cement and fly ash stabilized steel slag sand(C-FA-SS for short), are studied in this paper. The results show that the unconfined compressive strength performance of FA-SS is similar to L-FA-SS, and it can meet the highest strength when the ratio of steel slag to fly ash is 1:1~2:1. When the ratio of fly ash to the steel slag is 10:90, it is good to use cement stabilizing. Comparing the new road base materials with the traditional road base material, the former has better strength performance and economy function advantage.


Irriga ◽  
2018 ◽  
Vol 14 (4) ◽  
pp. 548-563 ◽  
Author(s):  
Rui Donizete Casarin ◽  
Eduardo Luiz de Oliveira

CONTROLE DE EROSÃO EM ESTRADAS RURAIS NÃO PAVIMENTADAS, UTILIZANDO SISTEMA DE TERRACEAMENTO COM GRADIENTE ASSOCIADO A BACIAS DE CAPTAÇÃO  Rui Donizete Casarin1; Eduardo Luiz de Oliveira21Faculdade de Ciências Agronômicas, Universidade Estadual Paulista, Botucatu, SP, [email protected] de Engenharia Civil, Universidade Estadual Paulista, Bauru, SP  1 RESUMO As estradas rurais de terra são estruturas viárias importantes para o desenvolvimento rural econômico e social da nação, sendo que a erosão provocada pelas águas das chuvas no seu leito e margens esta intimamente relacionada à má drenagem, tornando-se um dos principais fatores para sua degradação. Para que o sistema de drenagem funcione de forma adequada é necessário o conhecimento da erodibilidade, capacidade de infiltração de água no solo e adoção de práticas mecânicas de abatimentos de taludes com elevação do greide e interceptação de águas por meio de dispositivos de drenagem e captação. Neste artigo apresenta-se um modelo de drenagem por meio da construção de terraços embutidos com gradiente associados à bacia de captação em solos do tipo Argissolo Vermelho distrófico abrúptico de textura arenosa a média, com base em técnicas de abatimentos de taludes, elevando seu leito transversalmente das estradas com desviadores de fluxo. As frações granulométricas (areia, silte, argila) e a estabilidade de agregados indicam que esse solo sob ação antrópica pode apresentar processos erosivos resultando em escoamento superficial com arrastamento de solos, assoreando mananciais e cursos d’água localizados abaixo das estradas proporcionando grandes impactos ambientais nos corpos hídricos. A redução destes problemas de erosão nestas estradas de terra está na adoção de medidas que intercepte águas do próprio escoamento do seu leito, bem como as águas pluviais vindas de áreas adjacentes da contribuição, que são coletadas e conduzidas para terraços embutidos e bacias de captação. UNITERMOS: erosão em estradas rurais, infiltração de água no solo, práticas mecânicas de conservação de solo, contenção de águas pluviais.  CASARIN, R. D.; OLIVEIRA, E. L. CONTROL OF EROSION IN RURALUNPAVED ROADS UTILIZING A TERRACE  SYSTEM WITH GRADIENT ASSOCIATED TO CAPITATION BASIN  2 ABSTRACT             The agricultural unpaved roads are important road structures for the economic and social agricultural development of the Nation, and the erosion provoked by rain water in the road bed and sides are closely related to bad draining, one of the main factors for their degradation. In order to make the draining system adequate, it is necessary to know about  erodibility, infiltration capacity of water in the ground and adoption of mechanical slope abatement with grid elevation and water interception. This study presents  drainage model through the construction of terraces  with gradient  transversally associated to the capitation basin in  abruptic red dystrophic argisol soils, medium sandy texture, based on slops abatement  techniques, elevating the road bed and deviating flow. The grain sized fractions of this ground (sand, silt, clay) and the aggregate stability indicated that this ground, under anthropic action, presents erosive processes resulting in superficial draining with ground hauling, sanding sources and courses of water situation below roads, providing great environmental impacts in the hydric bodies. The reduction of erosion problems in these unpaved roads is in the adoption of measures that intercept waters from the draining of their stream bed itself, as well as pluvial waters comings from adjacent areas of contribution, that  are collected and conducted to inlaid terraces and capitation basis. KEYWORDS: erosion in agricultural roads, water infiltration in the soil, mechanical soil conservation practices, pluvial water containment.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Hao Zhang ◽  
Yuan Cheng ◽  
Lei Yang ◽  
Weikang Song

In order to increase the recycling of phosphogypsum waste, this study explored the feasibility of using phosphogypsum to replace some of the lime and aggregate in the lime-fly ash-crushed stone mixture which is a widely used road base material in China. For this purpose, compaction, compressive strength, composition structures, wetting-drying cycle tests, and shrinkage tests were carried out on the lime-fly ash-phosphogypsum-crushed stone composite to investigate its performance. The results indicate that lime-fly ash-crushed stone modified with phosphogypsum has the required strength of the road base material and favourable performances in environment (wetting-drying cycle) stability. The image processing analysis and shrinkage tests demonstrated that phosphogypsum can significantly improve the compactness and shrinkage performance of lime-fly ash-crushed stone mixture. A suitable content of phosphogypsum and a reasonable content of fine aggregate are conducive to improving the roadway engineering properties (i.e., decreasing shrinkage cracks and increasing compressive strength) of lime-fly ash-phosphogypsum-crushed stone composites.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Erhan Burak Pancar ◽  
Muhammet Vefa Akpınar

So many soil improvement methods have been developed in order to increase bearing capacity of superstructure of the road to be constructed on the soft clayey road base soils, decrease settlements, and increase other strength specifications (CBR,k,MRvalues, etc.). In this paper, lime stabilization of clayey road base soil with high water content and its improvement with geosynthetics (geocell + geotextile) reinforcement and comparisons of these two different improvement methods were made. For this purpose, plate loading experimental comparisons of clayey soil, which had high water content by 10% increasing the optimum water content, were made after it was improved with lime at the rates of 3, 6, and 12%, geotextile reinforcement, geocell reinforcement, geosynthetics reinforcement, and geosynthetics reinforcement + lime stabilization at various rates. It was understood that these improvement methods will not yield sufficient results on clayey soils with high water content on their own, and method of improvement with lime and then reinforcement with geosynthetics yields better results on these types of soils. Only one improvement state among ten different states examined in this study gave the sufficient results for the soil to be used for unpaved roads.


2010 ◽  
Vol 168-170 ◽  
pp. 2078-2081
Author(s):  
Zhan You Yan ◽  
Yu Shu ◽  
Jian Qing Bu ◽  
Xiang Guo Li

Fly-ash is an industrial waste burning pulverize coal boilers for thermal power plant and large enterprises, the steel slag is too a residue generated waste in steelmaking industrial processes, the average for every ton steel to produce half ton steel slag, steel slag and fly ash discharge amounts is very big, utilization ratio is very low. At present, a large number of steel slag is used of reclamation work, the remaining items is used rarely and large number is left storage. This paper is introduction steel slag and fly ash to do road base-course material, such can make good use of industry residue waste in large amount to reduce exploitation and cut down natural building stones, it is an application for ecological building materials again. Major study the steel slag and fly ash road features, these tests include materials compaction reality among them, mix design, unconfined compressive strength, split tensile strength, resilient modulus and other commonly used performance. Through comparative analysis, this two materials combination has good use of quality, it has greatly better than other materials such as lime-fly-ash stabilize crushed stone and lime-fly-ash soil and other materials. In particular, it has very good performance to reduce road base-course crack, the material has good resistance shrinkage and temperature shrinkage ability. Therefore, the combination of steel slag and fly ash can be done entirely road base-course and extend the road life.


2019 ◽  
Vol 46 (7) ◽  
pp. 601-608
Author(s):  
Mena I. Souliman ◽  
Ashish Tripathi ◽  
Lubinda F. Walubita ◽  
Mayzan M. Isied

Joint sealing in jointed plain concrete pavement (JPCP) has been practiced throughout the world for many years as it improves the performance of concrete pavements. The infiltration of water is a common problem in concrete pavements and often increases distresses, such as faulting and pumping. For this reason, sealing the joints can help reduce water infiltration. Additionally, the infiltration of sand and small stones, aggregates, or debris into the joints can also be prevented, consequently reducing joint spalling in concrete pavements. However, it is also reported that joint sealing increases the initial cost of construction, especially if the joints need to be resealed, which leads to some additional costs. In this study, the pavement distress data was collected from the long-term pavement performance (LTPP) database for all the JPCPs sections in North Texas. The study illustrates the relative field performance in terms of spalling, faulting, roughness, and deflections of JPCP sections for both sealed and unsealed LTPP sections of North Texas.


2013 ◽  
Vol 641-642 ◽  
pp. 574-577 ◽  
Author(s):  
Ying Tao Li ◽  
Ling Zhou ◽  
Mao Jiang ◽  
Yu Zhang ◽  
Jun Shao

In this paper, the mechanical property experiments of concrete based on the seawater and sea sand have been carried in different raw materials preparation and different conservation environments. The results show that the early strength and late strength of concrete based on seawater and sea sand are better than concrete based on freshwater and sand. There is no significant strength decreased for concrete based on seawater and sea sand under accelerated alternating wet and dry conditions. For concrete based on seawater and sea sand mixed with admixture, the downward trend of late strength is significantly delayed, the late strength of concrete based on the seawater and sea sand mixed with slag gets the most obvious growth trend, while the late strength of seawater and sea sand concrete mixed with fly ash gets the largest increment.


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