Dredged marine sand as constructive material

Abstract

Abstract:Dredging works are usually required to maintenance activities in many ports all over the world and represents a huge volume of disposal material. The use of dredged aggregates can be considered in several applications as erosive process control, coastal stabilization, beach replenishment, production of construction materials (clay, bricks, aggregates) or construction works (foundation fill, dikes, etc.). Researches revealed the feasibility of dredged marine sand (DMS) in the construction of base and sub-base harbour pavements incorporating this material to hydraulic binder mixes (cement or lime) in order to improve the grading of aggregates and correct the granular skeleton. Its main objective is to improve the packing and to obtain the compressive properties required for geotechnical applications. In this work the study of DMS from the Port of Sant Carles de la Rápita (Tarragona, Spain) as construction material is presented. The analysis of its influence on paste, mortar and concrete production is described. Two experimental phases were carried out once chemical and physical characteristics of DMS were determined. At first, pastes and mortars were made using CEM II/A-M 42,5R cement, different percentages of DMS on replacement of raw sand and plasticizer additive in order to obtain fresh and hardened properties of the mixes studied. After that, DMS was used in the production of concretes as fine aggregates. A pilot experience was carried out with concrete port pavements produced in industrial scale. Fresh and hardened properties of the concretes were determined and compared to the control mix. Results show satisfactory behaviour of DMS as construction material when incorporated in concrete as fine corrective sand.

Workability, strength, and shrinkage of ultra-high-performance seawater, sea sand concrete with different OPC replacement ratios

“…Faster hydration generates a greater amount of hydration products, such as calcium silicate hydrate (C-S-H), which blocks the pores in the resulting concrete and thus enhances the early strength development [2,16].…”

“…Relevant studies have demonstrated that the utilization of sea-sand [2,10] and seawater [11][12][13] in concrete increases early-age compressive strength, lowers long-term compressive strength [14,15], makes the concrete less workable [16], and increases drying shrinkage [17,18] compared to fresh water and river sand counterparts due to the salt and sea-shell contents present in them.…”

Editorial

“…As for the sustainable marine sediments management, this imposes a storage on ground of the non-or contaminated sediments and requires the development of processes of treatment and of reuse. The first paper, written by Limeira, Agulló, and Exteberria (2012), discusses a very important topic, which is the problem of dredged sediments. This work deals with the study of dredged marine sand from the Port of Sant Carles de la Ràpita (Tarragona, Spain) as construction material.…”

Characterizing Harbor Dredged Sediment for Sustainable Reuse as Construction Material

“…The third project served to enhance sediment into a landscaped eco-model; this project consisted of the implementation of landscaping eco-models made of sediments from 5 to 7 m high and covered with 0.25 m of topsoil to ensure the stability of the structure. In addition, dredged sediment has been used in some countries in major infrastructure projects, such us Palm Island in Dubai, Rotterdam harbor, the National Theatre in London and the artificial island of Chek Lap Kok where the Hong Kong airport is located [72,92,93]. The success of these projects confirms and verifies the economic and technical validity of reusing dredged sediment in civil engineering [94].…”