Preparation Of Multi Source Solid Waste Based Marine Grouting Material And Research On Its Performance

Marine engineering construction has entered a period of vigorous development in China.It often encounters submarine faults,landslides and other adverse geological bodies in the process of construction.At the same time,marine engineering buildings are often damaged by a variety of marine environmental factors.The existing marine engineering materials are lack of seawater erosion resistance,poor durability and high cost,so it is urgent to develop low-cost and high corrosion resistance marine engineering grouting materials.In this paper,the industrial solid waste with potential cementitious activity was used to prepare multi-source solid waste based marine grouting material matrix,and the method of mineral phase synthesis and matching design of multi-source solid waste based marine grouting material matrix was established.On this basis,the influence of solid waste gypsum and mineral admixtures on the working performance of marine grouting material was further studied,and the dynamic design method of working performance of multi-source solid waste based marine grouting material was established.Finally,the effects of seawater,Na2SO4 solution,NaCl solution and MgSO4 solution on the mechanical properties and anti-corrosion properties of multi-source solid waste based marine grouting materials were studied.The research results have great theoretical and practical significance for the development of high value-added utilization of industrial solid waste and the improvement of the quality of marine engineering construction in our country.The main research contents and results are as follows:The feasibility of preparing multi-source solid waste based marine grouting material matrix with Bayer red mud,carbide slag and silica fume as raw materials was studied.The effects of raw meal ratio,calcination temperature and holding time on the type and content of ferroaluminate phase,silicate phase and aluminate phase of multi-source solid waste based marine grouting material matrix were studied.The optimal rates of multi-source solid waste based marine grouting material matrix of KH,SM and IM were 0.79,1.70 and 0.86,respectively;The optimal heat treatment system is that the calcination temperature and holding time are 1400℃ and 60 min respectively.The matrix minerals are mainly composed of silicate phase and ferroaluminate phase,among which the content of β-C2S and C4AF in the mineral composition of matrix reaches 68.3 wt.%and 21 wt.%,respectively.The compressive strength of multi-source solid waste based marine grouting material meets the requirements.Based on the optimal raw meal ratio and heat treatment system,the performance control and optimization of multi-source solid waste based marine grouting materials were carried out.The effects of solid waste gypsum on rheological properties,mechanical properties and hydration process of multi-source solid waste based marine grouting materials were studied.The multi source solid waste based marine grouting materials belong to Herschel-Bulkley fluid;The order of performance optimization of gypsum is as follows:desulfurization gypsum>natural gypsum>phosphogypsum.Among them,when the content of desulfurized gypsum is 8 wt%,the mechanical properties and rheological properties of multi-source solid waste based marine grouting material are the best.The compressive strength of 3d,7d and 28d were 9.67 MPa,12.65 MPa and 16.70 MPa respectively,and the yield stress and plastic viscosity were 12.22 PA and 0.087 Pa·s respectively;The first exothermic peak increases with the increase of desulfurized gypsum and natural gypsum,and phosphogypsum was on the contrary.The appearance time of the second exothermic peak lags behind with the increase of the content of desulfurized gypsum,natural gypsum and phosphogypsum;The type of gypsum didn’t change the hydrate phase composition of marine grouting material.The influence of mineral admixtures on the performance of multi-source solid waste based marine grouting material was studied.Mineral admixtures didn’t change the Herschel-Bulkley fluid characteristics of multi-source solid waste based marine grouting material,and improves the plastic viscosity and yield stress of marine grouting material slurry.The mechanical properties of marine grouting materials were weakened by the effects of mineral powder,red mud,steel slag and fly ash in turn.When the mineral powder content was 20 wt.%,the compressive strength reached the maximum value,the strength reached 23.26 MPa in 28 days and the strength increased by 39.28%.10%mineral powder and red mud can promote the hydration of marine grouting materials,and the total amount of hydration heat release in 72 h was increased by 11.10%and 7.69%respectively;The total hydration heat release of 72 h of 10%fly ash and steel slag marine grouting material decreased by 7.39%and 7.47%respectively.The hydration products of multi-source solid waste based marine grouting material are mainly unhydrated calcium silicate,ettringite,calcium aluminate hydrate,hydrated calcium ferrite,two water gypsum,calcium hydroxide,gel solid solution and unreacted particles.The effects of seawater,Na2SO4 solution,NaCl solution and MgSO4 solution on the mechanical properties and anti-corrosion properties of multi-source solid waste based marine grouting materials were studied.The multi-source solid waste based marine grouting material with 8%desulfurized gypsum and 20%blast furnace slag has excellent mechanical properties and corrosion resistance,and the corrosion resistance coefficient is 1.17.Compared with pure water curing,the hydration products of multi-source solid waste based marine grouting materials can absorb erosion ions and react with SO42-in the erosion solution to form micro expansive erosion product ettringite,which improves the density of stone body and improves the anti erosion performance,and can meet the special technical requirements of marine environment.