Pre-wetted Lightweight Aggregate Research Articles

Enhancing the performance of lightweight high-performance concrete through an alternative pre-wetting method for lightweight aggregates using simulated cement pore solution

Lightweight aggregates (LWAs) are typically pre-wetted to prepare lightweight concrete. However, the incorporation of pre-wetted LWAs by water, may dilute the pore solutions of the cement matrix surrounding the LWAs during the process of internal curing. To this end, this paper proposes an alternative pre-wetting method for LWAs using simulated cement pore solutions (saturated Ca(OH)2 or real cement solution) instead of water. The effects of LWAs pre-wetted by various agents on the performance of lightweight high-performance concrete (LW-HPC) were investigated and compared. Experimental results confirmed that water released from LWAs diluted the pore solutions of cement in LW-HPCs. By using cement solution and Ca(OH)2 solution, the compressive strengths of LW-HPCs were respectively increased by 41.7% and 28.2% at 3d, and 11.6% and 3.2% at 28d compared with LWAs pre-wetted by water only. Among the three pre-wetting agents, the saturated cement solution was found to be the optimal one for promoting the hydration of cement, elastic modulus of the interfacial transition zone, and compressive strength.

Effect of Water-to-Cement Ratios on Performance of Concrete with Prewetted Lightweight Aggregates

Lightweight aggregates (LWAs), as a popular material for internal curing (IC), have been extensively utilized in internally cured concrete (ICC). This paper investigated the development of mechanical properties, restrained shrinkage, quantitative stress relaxation, and tensile creep of ICC with prewetted LWAs under the condition of diverse w/c ratios (0.33, 0.40, and 0.50) by experimental investigations. Besides, the mixture proportion without IC was designed to investigate the effect of IC on the performance of the concrete mixture with a w/c ratio of 0.50. Corresponding results show that increasing the w/c ratio diminished the mechanical properties of ICC. A decrease in residual stress and stress rate was related to an increase in the w/c ratio. Relaxed stress and tensile creep increased with the w/c ratio increasing in ICC in the initial days. The introduction of IC decreased the mechanical properties, restrained shrinkage, stress rate, relaxed stress, and tensile creep of the concrete mixture with a w/c ratio of 0.50. The relationship between creep and relaxation coefficients was established, which contributed to the accurate evaluation of tensile stress development of ICC with prewetted LWAs under restrained conditions.

Evaluating the Effect of Incorporating Slag Cement with Pre-wetted Lightweight Aggregate on Reducing Cracking of Concrete Bridge Decks

Abstract Early-age cracking is a severe problem in concrete bridges because it reduces the durability of the superstructure. One of the techniques to minimize early-age cracks is the addition of pre-wetted lightweight aggregate (LWA). There is limited research regarding the effect of pre-wetted LWA on the early-age performance of concrete. This paper aims to evaluate the efficiency of incorporating slag cement with pre-wetted LWA to reduce the potential cracking of the concrete decks. Also, the effect of fly ash on the shrinkage properties of concrete was investigated. Mixtures used in this study consist of replacements of total aggregate with pre-wetted LWA and partial replacements of cement with slag cement or fly ash. The performance of concrete specimens containing slag cement with pre-wetted LWA was evaluated in terms of mechanical properties, plastic shrinkage, free shrinkage, and restrained shrinkage. The results showed that the tensile strength was not the most significant parameter affecting the cracking potential of the concrete. The cracking potential of the concrete was strongly related to the tensile strength and free shrinkage. It was observed that incorporating slag cement with pre-wetted LWA significantly enhances the early-age performance of concrete as the tested specimens showed no sign of cracks. The results also showed that the shrinkage of the mixtures containing coarse LWA was reduced by 43 % compared with the control mixture. Moreover, it was noted that the LWA with higher absorption increases plastic shrinkage cracks for concrete decks under severe conditions.

Experimental investigation and reliability prediction of high performance concrete based on lightweight aggregate under 4-point bending loading

The damage of lightweight aggregate high performance concrete (LHPC) under four-point bending was experimentally investigated. The effects of stress level and loading age on LHPC damage were elucidated. The research results show that with the increase of stress level, the damage of LHPC is gradually aggravated, but it also stimulates the internal curing effect of lightweight aggregate (LWA). The internal curing effect of pre-wetted lightweight aggregate (PLWA) promotes the formation of hydration products such as C-S-H gel, which can slow down the damage of LHPC under loading. When the stress level is 50%− 70% ultimate load (Pcr), LHPC is partially damaged under continuous bending, and its corrosion resistance coefficient (Kf) and relative dynamic elastic modulus (Erd) are reduced, but it still has a certain carrying capacity. The LHPC under the action of 90% Pcr was completely damaged in 11588 s, and the LHPC under the action of 95% Pcr was completely damaged in 1096 s. Under a given stress level, the fatigue life of LHPC can be simulated by a two-parameter Weibull distribution. Therefore, a reliability evaluation method is proposed to obtain the fatigue life prediction of LHPC under 4-point bending loading.

Effect of nano-silica on the mechanical performance and microstructure of silicon-aluminum-based internal-cured concrete

This study explores the effect of nano-silica on the performance of internal-cured concrete (ICC) with silicon-aluminum-based lightweight aggregate (LWA) by evaluating the mechanical behavior, microstructure of the matrix and the ITZ between LWA and the surrounding paste and phases of hydration products. Adding nano-silica significantly increased the compressive, split-tensile and flexural strength with a maximum increase of 63.7%, 17.6% and 11.3%, respectively, at a 1.0 wt% dosage. Although nano-silica presented a good filling, nucleation and pozzolanic effect, a higher dosage of 2.5 wt% resulted in a minor negative consequence on concrete microstructure given that a visible gap was identified between LWA and the neighboring paste, leading to a reduction in mechanical performance. The additional water provided by the pre-wetted LWA can compensate for the decreased water absorbed by nano-silica to prevent the decline of relative humidity and promote hydration reactions. In addition to the internal curing effect, the silicon-aluminum-based LWA also presented pozzolanic reactivity and exhibited a good coupling effect with nano-silica, contributing to a strengthened microstructure with a large amount of C–S–H gel tightly bonded and intertwined with other morphologies of hydration products. An increase in internal-water to binder ratio from 0.012 to 0.036 improved the densification of the paste and the composition of hydration products but the impact is less significant. With the good combined effect of nano-silica and internal curing, the mixture with 40% LWA presented excellent mechanical properties.

Mechanical properties and microstructure of ultra-high strength concrete with lightweight aggregate

In recent years, the development of concrete has been toward to the direction of lightweight and high strengthening. This study developed a kind of lightweight ultra-high strength concrete(L-UHSC) through the comprehensive design method, which had an apparent density rang of 1995 kg/m3-2114 kg/m3 and a compressive strength of 102.4–114.5 MPa. The specific strength of the designed L-UHSC is more than 50 MPa/(t/m3), which is higher than ordinary structural lightweight aggregate concrete (LAC). Additionally, the roles of high-performance paste, lightweight aggregate (LWA) and steel fiber in L-UHSC were revealed through scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP) and strength test. The findings revealed that SF content, rather than the binder-sand ratio and aggregate ratio, has a greater impact on density and strength, and the aggregate ratio having the least effect. As steel fiber content increases from 0.5 % to 2.0 %, compressive strength, flexural strength and splitting tensile strength of LAC increase by 44.3 %, 120 % and 151 %, respectively, which is higher than that of ultra-high performance (UHPC). The micromorphology and pore structure research suggested that the high-performance paste plays a keystone role in achieving the ultra-high strength, and LWAs mainly affected strength through improving pore structure. In addition, small size pre-wetted LWA is more conducive to concrete strength. Our preliminary results provide a reference for the research and development of lightweight ultra-high strength cement composites.

Relationship between internal relative humidity and autogenous shrinkage of early‐age concrete containing prewetted lightweight aggregates

AbstractInternal curing (IC) agents such as prewetted lightweight aggregates (LWAs) have been proved to be advantageous in reducing the autogenous shrinkage and early‐age cracking of concrete by introducing additional water. Quantitative analyses of internal relative humidity (IRH) of concrete are essential to better estimate the autogenous shrinkage of early‐age concrete. Existing studies investigate the IRH or autogenous shrinkage of early‐age concrete, respectively; however, the relevance between them of concrete containing prewetted LWAs remain lacking. Accordingly, the IRH, autogenous shrinkage, and the correlation between them for early‐age concrete with various LWAs replacement ratios were investigated. A noncontact device was utilized to measure the IRH and autogenous shrinkage of concrete simultaneously. Test results suggested that: (1) the absolute value of the maximum expansion increased from 0 με to 20, 50, and 96 με when the proportion of prewetted LWAs increased from 0% to 10%, 30%, and 50%, respectively; (2) compared with Mixture LWA00, the autogenous shrinkage at 28 days decreased by 14.7%, 36.3%, and 62.6% for Mixture LWA10, LWA30, and LWA50, respectively; (3) the IRH at 28 days or the critical time of IRH was 88.7%, 90.1%, 93.2%, and 95.9% RH or 5, 6, 8, and 10 days for Mixture LWA00, LWA10, LWA30, and LWA50, respectively; (4) a prediction model for the evaluation of the autogenous shrinkage was constructed based on IRH of early‐age concrete considering the quantity of IC water introduced by various replacement ratios of LWAs.

Tensile creep behavior of Alkali-activated slag concrete incorporating lightweight aggregate

This study aims to investigate the effect of pre-wetting lightweight aggregate (LWA) on the tensile creep of alkali-activated slag concrete (AASC) for 14 d. Three replacement rates of natural coarse aggregate with LWA were used in this study, including 0, 50%, and 100%, and the Ordinary Portland cement concretes (OPCCs) mixed with LWAs were considered as control samples. The results showed that the tensile creep of the AASCs was higher than those of OPCCs with the same LWA content. The incorporation of pre-wetting LWA significantly reduced the modified autogenous shrinkage and tensile creep of the AASCs, and the magnitudes were continuously declined with the increase in LWA contents. The early age of 1 d dominated more than 70% of the total tensile creep of the AASCs for 14 d. Furthermore, pre-wetting LWAs had a greater effect on decreasing tensile creep for the AASC system than the OPCC system. Meanwhile, the creep/shrinkage ratio of the AASCs was declined by the addition of pre-wetting LWAs. In addition, the cracking age of the AASC was desirably delayed by adding pre-wetting LWA, and the effect was more noticeable with the increase in LWA contents.

Internal Curing Effect of Waste Glass Beads on High-Strength Cement Composites

High-strength concrete (HSC) uses binders and microfillers with ultrafine particles, such as silica fume. The resulting dense internal hydration structure rapidly decreases HSC humidity, causing shrinkage cracks and affecting internal hydration. Herein, the hydration degree inside high-strength cement composites (HSCCs) was examined using waste glass beads (WGBs) as lightweight aggregates (LWAs). Moreover, unreacted hydrate reduction and hydrate formation tendencies were investigated. WGBs with particle sizes within 2.00–6.00 mm were added at ratios of 5%, 10%, and 20% after pre-wetting. The increased number of hydrates inside the specimens were examined under steam curing (80 °C) and room temperature curing (25 °C). The strength decreased as the WGB content increased. Thermogravimetric, X-ray diffraction, and Si nuclear magnetic resonance analyses revealed that the hydration degree of Si inside HSCCs changed when the content of pre-wetted LWAs changed. A visual inspection of the specimen cross-section and scanning electron microscopy–energy-dispersive X-ray spectrometry (SEM–EDS) analysis revealed the moisture trapped inside WGB pores and the hydration tendency. Under steam curing and room temperature curing, the paste contained different amounts of hydrates, depending on WGB content. Moreover, water-absorbed WGBs were continuously desorbed through SEM–EDS, and hydrates were present in WGB pores.

Influence of multi-walled carbon nanotubes on the multi-scale performance of internally cured concrete containing pre-wetted lightweight aggregate

Multi-walled carbon nanotubes (MWCNTs) is an effective reinforcing nanomaterial in concrete given its outstanding filling, nucleation and bridging effects. This study evaluates the enhancement of MWCNTs on internally cured concrete (ICC) containing pre-wetted lightweight aggregate (LWA) through mechanical tests, SEM-EDS and XRD evaluations. The variations in the dosages of MWCNTs and LWA and the connection between water-to-binder (w/b) ratios and MWCNT dosages were considered. Results show that adding MWCNTs benefits the mechanical performance of LWA-ICC but at a dosage of less than 0.25 wt%. A richer C–S–H phase can be identified in both the interfacial transition zone and the general matrix with the addition of MWCNTs. The internal curing of LWA presents a positive synergistic effect with MWCNTs and can offset the adverse influence of LWA’s low-strength given a dosage of less than 40 vol%. An increased w/b ratio leads to a porous microstructure with a richer phase in calcium hydroxide, resulting in decreased mechanical performance. However, the negative effect of a high w/b ratio, i.e., 0.55, on concrete performance can be improved given a higher MWCNT dosage of 0.25 wt%.

Cracking resistance and sustainability assessment of alkali-activated slag concrete incorporating lightweight aggregate

This study aims to evaluate the cracking resistance and sustainability performance of alkali-activated slag (AAS) concretes incorporating pre-wetted lightweight aggregates (LWAs). Three replacement rates (0, 50%, and 100%) of natural coarse aggregates (NAs) with pre-wetted LWAs are used, while the ordinary Portland cement (OPC) concrete alternatives are considered as control samples. The results showed that incorporating pre-wetted LWAs effectively improved the cracking resistance of the AAS concretes, and the effect was more evident as the LWA contents increased. The cracking age of the AAS concretes was delayed from 5.6 d to 8.9 d and 10.6 d with 50% and 100% replacement of NAs by LWAs, respectively. Meanwhile, a desirable result was that the AAS concretes could still endure relatively high tensile stress after the initial cracking. The larger tensile stress could be undertook with the increase in LWA contents. Although the incorporation of LWA slightly increased the environmental burdens of the concrete alternatives, the energy consumption and five environmental impact categories of the AAS concretes were reduced by more than 20% and 40%, respectively, compared to those of OPC concretes with the same LWA content. Similar results were found in the calculation of life-cycle cost. Even for the AAS concretes with 100% LWA content, the significant environmental and economic benefits were still obviously obtained compared to the OPC concretes without LWA.

Measuring the influence of Pre-Wetted Lightweight aggregates on concrete's surface resistivity

This study evaluated the influence of pre-wetted lightweight aggregates (LWAs) typically used for internal curing applications on concrete’s 28-day strength and surface resistivity over time. Ninety-six concrete mixtures were prepared to identify the effects of three coarse aggregate types, two water-to-cementitious (w/cm) ratios, three LWA sources, and four variations of supplementary cementitious materials (SCMs). The compressive strength tests showed that LWAs generally had a positive effect on strength. While some exceptions were observed where LWAs had lower strengths than the controls, all LWA specimens met the 27.6 MPa strength requirements for structural concrete in Louisiana. Concerning surface resistivity, a statistical analysis determined that the use of SCMs, w/cm ratio, coarse aggregate type, and LWAs all had significant effects. The samples containing SCMs significantly outperformed the specimens prepared with only portland cement. The w/cm ratio had a high impact in resistivity. The coarse aggregate type also had an effect on resistivity based on the porosity of the aggregate itself, rather than the mineralogy. Lastly, LWAs had an overall positive effect on resistivity, performing similarly or better than the control specimens in most cases. Based on these results, internal curing through pre-wetted LWAs is expected to be compatible with specifications from state highway agencies (SHAs) that have a performance requirement with surface resistivity.

Development of high performance lightweight concrete using ultra high performance cementitious composite and different lightweight aggregates

To reduce the dead load of concrete structures, this study developed a high performance lightweight aggregate concrete (HPLAC) by combining the use of ultra high performance cementitious composite (UHPC) and different types of aluminosilicate lightweight aggregates (LWAs). The physicochemical properties of two types of LWAs (i.e. expanded clay and expanded shale) influencing the HPLAC were elaborated and compared. The composition distribution and micromechanical properties in the interfacial regions of paste and LWAs were revealed by elemental mapping and nanoindentation. The results showed that the incorporation of the clay LWAs or shale LWAs in the HPLAC led to similar density and thermal conductivity values, while the use of the shale LWAs induced a lower water absorption and higher strength of HPLAC as compared to the clay LWAs due to the fine pore structure and higher pozzolanic activity of the former. The internal curing effect provided by the pre-wetted shale LWAs was more efficient in enhancing the hydration of binder, and the Al dissolution from the shale LWAs further densified the interfacial bonding to form a dense rim surrounding LWAs, resulting in improved micromechanical properties at the interface. The X-ray CT results indicated that the adoption of UHPC was beneficial to preventing segregation of the LWAs and steel fibers in the HPLAC. By virtue of the physical-chemical interactions of LWAs, the synergetic use of UHPC and pre-wetted shale LWAs was able to produce an HPLAC with high structural efficiency, good thermal insulation, low autogenous shrinkage and permeability.

The role of moisture transport mechanisms on the performance of lightweight aggregates in internal curing

Internal curing (IC) of concrete by pre-wetted lightweight aggregate (LWA) is an established technology to assist cement hydration and reduce shrinkage and cracking in concrete. However, the current understanding in what makes a certain LWA effective for IC gives opportunities to improve the technique. The aim of this article is to identify the moisture transport mechanisms within an LWA that govern IC performance. Results on LWA of different internal structures (natural, manufactured), and different size distributions (fine, coarse), pre-soaked with either pure water or water containing shrinkage reducing admixtures (SRA), indicate that there are different mechanisms involved in water uptake and release: one controlled by capillary action, and one controlled by air diffusion into the pore water. It is concluded that it is the internal structure, geometry, and particle size distribution of the LWA that determine the effect of SRA and the overall LWA impact on the IC performance. By using 3D micro-CT images LWAs are studied in order to determine which characteristics (pore size, pore connectivity, pore distribution) are better suited for improving IC. This contribution to understanding water transport in LWAs may help to engineer the characteristics of LWA optimized for IC applications.

Autogenous Shrinkage of Internally Cured Conventional, Latex-Modified, and Very High Early Strength Latex-Modified Concrete and Mortar

Abstract Internally cured concrete has been shown to help mitigate early-age cracking and to provide improved durability performance in concrete elements. The increased absorptive capacity of lightweight aggregates (LWA) facilitates delivery of moisture to concrete internally during the curing process. In this study, a range of concrete mortar mixtures representative of mortar contained in bridge deck and pavement concrete mixtures were batched and tested for autogenous shrinkage. Two significantly different LWAs were utilized in this study: one LWA with an absorption typical of most manufactured LWA and one with a relatively low absorption for a manufactured LWA. Autogenous shrinkage test results clearly demonstrated the impact of use of prewetted LWA for internal curing. Reductions in autogenous strain ranged from 30 to 56 % depending on the type of LWA used as well as the percentage replacement of prewetted LWA for normal-weight fine aggregate. The reduction in autogenous shrinkage correlated with LWA replacement rate, and shrinkage was even further reduced for mixtures that included fly ash. Findings indicated that the lower-absorption LWA provides internal curing benefits when used at suitable replacement levels, which may exceed those currently specified by some state highway agencies. Use of the approach to computing LWA substitution rate provided in ACI (308-213)R-13, Report on Internally Cured Concrete Using Prewetted Absorptive Lightweight Aggregate, should provide adequate moisture delivery to support reduction in autogenous shrinkage and internal curing benefits and is suitable for proportioning of both the typical and lower absorption LWA to support internal curing. In addition to reduced autogenous shrinkage, use of prewetted LWA in very high early strength latex-modified concrete mixtures provided workability and work-time advantages.

Effect of pre-wetted lightweight aggregates on residual stress development and stress relaxation in restrained concrete ring specimens

With the continuous progress of concrete technology, concrete with the low water-to-cement (w/c) ratio is utilized extensively. Concrete suffers significant shrinkage due to the high self-desiccation at early age. When shrinkage of concrete is hindered by the restraint, the tensile stress will develop and cause the generation of cracks. For reducing the shrinkage, internal curing (IC) has been employed in concrete by introducing the additional water which can be preserved in pre-wetted lightweight aggregates (LWAs). Although a number of studies focus on the results from autogenous and drying shrinkage, the result of the effect of IC with LWAs on the performance of concrete with low w/c ratio is still limited. In present study, the investigations on the stress relaxation and time to cracking of concrete with the different proportions of pre-wetted LWAs (0%, 10%, 30%, and 50% by the volume replacement of normal weight coarse aggregates) were conducted by the restrained ring test. Results obtained from tests were shown as follows: (1) the strain of steel ring decreased with the increase of the proportion of pre-wetted LWAs; (2) the maximum residual stress of concrete mixture decreased with the increase of the proportion of pre-wetted LWAs; (3) the relaxed stress of concrete mixture decreased with the increase of the proportion of pre-wetted LWAs at the different age; (4) the stress rate of concrete mixture decreased with the increase of the proportion of pre-wetted LWAs; (5) although the concrete mixture with the 50% proportion of pre-wetted LWAs cracked at the earliest age, the time to cracking was postponed when the proportion of pre-wetted LWAs increased from 0% to 30%.

Modelling on temperature field of high-strength concrete pavement with the impact of internal curing

ABSTRACT A numerical model for the temperature field calculation of high-strength concrete pavement is developed in this paper. Cement hydration, solar radiation and atmospheric temperature changes are taken into consideration in the modelling. Temperature field of high-strength concrete pavement made by concrete with a compressive strength of 100 MPa at 28 days is simulated. Using the model, effects of internal curing with pre-wetted lightweight aggregate (PSLWA) in concrete, concrete casting time, casting season and concrete strength on the development of temperature in the pavement are studied. The model results show that internal curing with PSLWA will increase the temperature rise in the pavement of 2°C compared with the reference. The effect of construction seasons of the pavement on temperature rise is significant. About 20°C lower temperature rise may be expected if the pavement is constructed in spring instead of in summer. The model predictions and test results on the development of temperature at different places in the slab agreed well and the model may be used for temperature control and optimisation of pavement construction.

Experimental study on shrinkage reduction of calcium sulphoaluminate cement concrete with addition of pre-wetted lightweight aggregate

In the present paper, shrinkage reduction with pre-wetted LWA of calcium sulphoaluminate cement (CSA) concrete is experimentally investigated. In the test programs, shrinkage of low, medium and high strength CSA concrete with and without internal curing with pre-wetted LWA is measured. Water movement between a single pre-wetted ceramsite particle and the surrounding cement paste during cement hydration is directly measured through a glass tube connected with the ceramsite. The test results show that the main component of shrinkage of CSA concrete, no matter low or high strength concrete, is autogenous shrinkage other than drying shrinkage. Autogenous shrinkage of high strength CSA concrete is much higher than that of low strength CSA concrete. The addition of pre-wetted LWA can greatly reduce the autogenous shrinkage of CSA concrete even the internal curing water to cement ratio used in the concrete is as low as 0.04. The efficiency of shrinkage reduction is influenced by concrete strength or water to binder ratio. The higher the strength, the greater the shrinkage reduction. Water contained in LWA starts to release at about 15–25 min after mixing depending on water to binder ratio of the cement paste. Water movement between LWA and surrounding cement matrix during cement hydration obeys a two-stage mode, a fast releasing stage followed with a slow releasing stage. Amount of releasing water from LWA is obviously influenced by the initial air content in the LWA and the water to binder ratio of the paste. As air content is varied between 0 and 50% in volume, the more the air content, the more the water moved out of LWA. For given initial air content, the lower the water to binder ratio, the more the water removed from the LWA.

Structural response of concrete pavement slabs under hygrothermal actions

This paper presents a comprehensive evaluation of the structural response of concrete pavement slabs subjected to ambient environmental actions. Experimental data come from six bonded concrete overlay of asphalt pavements built with rapid strength concrete mixtures. The mixtures contained either portland cement or calcium sulfoaluminate cement, and included an internally cured concrete with pre-wetted lightweight aggregates. The pavement slabs were instrumented with temperature, relative humidity, and strain sensors. The measured temperatures and strains were analyzed by using a model that includes two components, one for moisture-related shrinkage and another for thermal deformations. The analysis of data collected over fifteen months shows that the ambient environment actions considerably impact the coefficient of thermal expansion (CTE) of pavement slabs concrete. Because of drying, the thermal deformations of the slabs were up to 65% larger than predicted based on the CTE determined in the laboratory under saturated conditions following AASHTO T 336. The analysis of the experimental data supplements the understanding of how drying and autogenous shrinkage accumulates in concrete pavement slabs in the field, depending on mixture type and weather conditions. Experimental results from this study question the validity of a number of assumptions adopted in current mechanistic-empirical design procedures for concrete pavements, including the constant CTE of the concrete and the depth of drying penetration in pavement slabs.

Internal Curing Efficiency of Pre-Wetted Lightweight Fine Aggregates on Strength Parameters of Concrete

Internal cured concrete (ICC) using pre-wetted lightweight aggregates is to replace conventional type of curing. Normally curing for conventional type is done by external to internal, which requires a large membrane and a large amount of water is required to do this type of procedure and the water which we use for curing may get runoff or get evaporated. But in ICC type of curing it cure inside to outside, the pre-wetted lightweight aggregates provides sufficient moisture to hydrate cement inside the concrete. The pre-wetted light weight aggregates, which stores water inside and acts as a reservoir. It release water when hydration process is done. Lightweight aggregates such as expanded clay or shale, vermiculite, pumice, slate, perlite having high water absorbing capacity are generally used for internal cured concrete. In this study, vermiculite and expanded clay had been used as replacements of fine aggregate, 2.5%, 5%, 7.5%, 10% and 12.5% are replaced for vermiculite and 5%, 10%, 15%, 20% and 25% for expanded clay.